Merge pull request #4443 from radarhere/assert

Converted most assert statements to pytest

Tests/check_libtiff_segfault.py

@@ -1,5 +1,6 @@
 import unittest
 
+import pytest
 from PIL import Image
 
 from .helper import PillowTestCase
@@ -13,7 +14,7 @@ class TestLibtiffSegfault(PillowTestCase):
             libtiff >= 4.0.0
             """
 
-        with self.assertRaises(IOError):
+        with pytest.raises(IOError):
             with Image.open(TEST_FILE) as im:
                 im.load()
 

Tests/check_png_dos.py

@@ -20,10 +20,10 @@ class TestPngDos(PillowTestCase):
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
         for s in im.text.values():
-            self.assertLess(len(s), 1024 * 1024, "Text chunk larger than 1M")
+            assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
         for s in im.info.values():
-            self.assertLess(len(s), 1024 * 1024, "Text chunk larger than 1M")
+            assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
     def test_dos_text(self):
 
@@ -31,11 +31,11 @@ class TestPngDos(PillowTestCase):
             im = Image.open(TEST_FILE)
             im.load()
         except ValueError as msg:
-            self.assertTrue(msg, "Decompressed Data Too Large")
+            assert msg, "Decompressed Data Too Large"
             return
 
         for s in im.text.values():
-            self.assertLess(len(s), 1024 * 1024, "Text chunk larger than 1M")
+            assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
     def test_dos_total_memory(self):
         im = Image.new("L", (1, 1))
@@ -54,15 +54,13 @@ class TestPngDos(PillowTestCase):
         try:
             im2 = Image.open(b)
         except ValueError as msg:
-            self.assertIn("Too much memory", msg)
+            assert "Too much memory" in msg
             return
 
         total_len = 0
         for txt in im2.text.values():
             total_len += len(txt)
-        self.assertLess(
-            total_len, 64 * 1024 * 1024, "Total text chunks greater than 64M"
-        )
+        assert total_len < 64 * 1024 * 1024, "Total text chunks greater than 64M"
 
 
 if __name__ == "__main__":

Tests/helper.py

@@ -240,7 +240,7 @@ class PillowLeakTestCase(PillowTestCase):
             core()
             mem = self._get_mem_usage() - start_mem
             msg = "memory usage limit exceeded in iteration %d" % cycle
-            self.assertLess(mem, self.mem_limit, msg)
+            assert mem < self.mem_limit, msg
 
 
 # helpers

Tests/test_color_lut.py

@@ -1,6 +1,7 @@
 import unittest
 from array import array
 
+import pytest
 from PIL import Image, ImageFilter
 
 from .helper import PillowTestCase, assert_image_equal
@@ -74,10 +75,10 @@ class TestColorLut3DCoreAPI(PillowTestCase):
         with self.assertRaisesRegex(ValueError, r"size1D \* size2D \* size3D"):
             im.im.color_lut_3d("RGB", Image.LINEAR, 3, 2, 2, 2, [0, 0, 0] * 9)
 
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             im.im.color_lut_3d("RGB", Image.LINEAR, 3, 2, 2, 2, [0, 0, "0"] * 8)
 
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             im.im.color_lut_3d("RGB", Image.LINEAR, 3, 2, 2, 2, 16)
 
     def test_correct_args(self):
@@ -240,14 +241,14 @@ class TestColorLut3DCoreAPI(PillowTestCase):
                                   -1,  2,  2,   2,  2,  2,
                               ])).load()
         # fmt: on
-        self.assertEqual(transformed[0, 0], (0, 0, 255))
-        self.assertEqual(transformed[50, 50], (0, 0, 255))
-        self.assertEqual(transformed[255, 0], (0, 255, 255))
-        self.assertEqual(transformed[205, 50], (0, 255, 255))
-        self.assertEqual(transformed[0, 255], (255, 0, 0))
-        self.assertEqual(transformed[50, 205], (255, 0, 0))
-        self.assertEqual(transformed[255, 255], (255, 255, 0))
-        self.assertEqual(transformed[205, 205], (255, 255, 0))
+        assert transformed[0, 0] == (0, 0, 255)
+        assert transformed[50, 50] == (0, 0, 255)
+        assert transformed[255, 0] == (0, 255, 255)
+        assert transformed[205, 50] == (0, 255, 255)
+        assert transformed[0, 255] == (255, 0, 0)
+        assert transformed[50, 205] == (255, 0, 0)
+        assert transformed[255, 255] == (255, 255, 0)
+        assert transformed[205, 205] == (255, 255, 0)
 
         # fmt: off
         transformed = im._new(im.im.color_lut_3d('RGB', Image.LINEAR,
@@ -260,14 +261,14 @@ class TestColorLut3DCoreAPI(PillowTestCase):
                                   -3,  5,  5,   5,  5,  5,
                               ])).load()
         # fmt: on
-        self.assertEqual(transformed[0, 0], (0, 0, 255))
-        self.assertEqual(transformed[50, 50], (0, 0, 255))
-        self.assertEqual(transformed[255, 0], (0, 255, 255))
-        self.assertEqual(transformed[205, 50], (0, 255, 255))
-        self.assertEqual(transformed[0, 255], (255, 0, 0))
-        self.assertEqual(transformed[50, 205], (255, 0, 0))
-        self.assertEqual(transformed[255, 255], (255, 255, 0))
-        self.assertEqual(transformed[205, 205], (255, 255, 0))
+        assert transformed[0, 0] == (0, 0, 255)
+        assert transformed[50, 50] == (0, 0, 255)
+        assert transformed[255, 0] == (0, 255, 255)
+        assert transformed[205, 50] == (0, 255, 255)
+        assert transformed[0, 255] == (255, 0, 0)
+        assert transformed[50, 205] == (255, 0, 0)
+        assert transformed[255, 255] == (255, 255, 0)
+        assert transformed[205, 205] == (255, 255, 0)
 
 
 class TestColorLut3DFilter(PillowTestCase):
@@ -301,20 +302,20 @@ class TestColorLut3DFilter(PillowTestCase):
 
     def test_convert_table(self):
         lut = ImageFilter.Color3DLUT(2, [0, 1, 2] * 8)
-        self.assertEqual(tuple(lut.size), (2, 2, 2))
-        self.assertEqual(lut.name, "Color 3D LUT")
+        assert tuple(lut.size) == (2, 2, 2)
+        assert lut.name == "Color 3D LUT"
 
         # fmt: off
         lut = ImageFilter.Color3DLUT((2, 2, 2), [
             (0, 1, 2), (3, 4, 5), (6, 7, 8), (9, 10, 11),
             (12, 13, 14), (15, 16, 17), (18, 19, 20), (21, 22, 23)])
         # fmt: on
-        self.assertEqual(tuple(lut.size), (2, 2, 2))
-        self.assertEqual(lut.table, list(range(24)))
+        assert tuple(lut.size) == (2, 2, 2)
+        assert lut.table == list(range(24))
 
         lut = ImageFilter.Color3DLUT((2, 2, 2), [(0, 1, 2, 3)] * 8, channels=4)
-        self.assertEqual(tuple(lut.size), (2, 2, 2))
-        self.assertEqual(lut.table, list(range(4)) * 8)
+        assert tuple(lut.size) == (2, 2, 2)
+        assert lut.table == list(range(4)) * 8
 
     @unittest.skipIf(numpy is None, "Numpy is not installed")
     def test_numpy_sources(self):
@@ -324,30 +325,30 @@ class TestColorLut3DFilter(PillowTestCase):
 
         table = numpy.ones((7, 6, 5, 3), dtype=numpy.float16)
         lut = ImageFilter.Color3DLUT((5, 6, 7), table)
-        self.assertIsInstance(lut.table, numpy.ndarray)
-        self.assertEqual(lut.table.dtype, table.dtype)
-        self.assertEqual(lut.table.shape, (table.size,))
+        assert isinstance(lut.table, numpy.ndarray)
+        assert lut.table.dtype == table.dtype
+        assert lut.table.shape == (table.size,)
 
         table = numpy.ones((7 * 6 * 5, 3), dtype=numpy.float16)
         lut = ImageFilter.Color3DLUT((5, 6, 7), table)
-        self.assertEqual(lut.table.shape, (table.size,))
+        assert lut.table.shape == (table.size,)
 
         table = numpy.ones((7 * 6 * 5 * 3), dtype=numpy.float16)
         lut = ImageFilter.Color3DLUT((5, 6, 7), table)
-        self.assertEqual(lut.table.shape, (table.size,))
+        assert lut.table.shape == (table.size,)
 
         # Check application
         Image.new("RGB", (10, 10), 0).filter(lut)
 
         # Check copy
         table[0] = 33
-        self.assertEqual(lut.table[0], 1)
+        assert lut.table[0] == 1
 
         # Check not copy
         table = numpy.ones((7 * 6 * 5 * 3), dtype=numpy.float16)
         lut = ImageFilter.Color3DLUT((5, 6, 7), table, _copy_table=False)
         table[0] = 33
-        self.assertEqual(lut.table[0], 33)
+        assert lut.table[0] == 33
 
     @unittest.skipIf(numpy is None, "Numpy is not installed")
     def test_numpy_formats(self):
@@ -386,7 +387,7 @@ class TestColorLut3DFilter(PillowTestCase):
 
     def test_repr(self):
         lut = ImageFilter.Color3DLUT(2, [0, 1, 2] * 8)
-        self.assertEqual(repr(lut), "<Color3DLUT from list size=2x2x2 channels=3>")
+        assert repr(lut) == "<Color3DLUT from list size=2x2x2 channels=3>"
 
         lut = ImageFilter.Color3DLUT(
             (3, 4, 5),
@@ -395,8 +396,9 @@ class TestColorLut3DFilter(PillowTestCase):
             target_mode="YCbCr",
             _copy_table=False,
         )
-        self.assertEqual(
-            repr(lut), "<Color3DLUT from array size=3x4x5 channels=4 target_mode=YCbCr>"
+        assert (
+            repr(lut)
+            == "<Color3DLUT from array size=3x4x5 channels=4 target_mode=YCbCr>"
         )
 
 
@@ -417,25 +419,25 @@ class TestGenerateColorLut3D(PillowTestCase):
 
     def test_3_channels(self):
         lut = ImageFilter.Color3DLUT.generate(5, lambda r, g, b: (r, g, b))
-        self.assertEqual(tuple(lut.size), (5, 5, 5))
-        self.assertEqual(lut.name, "Color 3D LUT")
+        assert tuple(lut.size) == (5, 5, 5)
+        assert lut.name == "Color 3D LUT"
         # fmt: off
-        self.assertEqual(lut.table[:24], [
+        assert lut.table[:24] == [
             0.0, 0.0, 0.0,  0.25, 0.0, 0.0,  0.5, 0.0, 0.0,  0.75, 0.0, 0.0,
-            1.0, 0.0, 0.0,  0.0, 0.25, 0.0,  0.25, 0.25, 0.0,  0.5, 0.25, 0.0])
+            1.0, 0.0, 0.0,  0.0, 0.25, 0.0,  0.25, 0.25, 0.0,  0.5, 0.25, 0.0]
         # fmt: on
 
     def test_4_channels(self):
         lut = ImageFilter.Color3DLUT.generate(
             5, channels=4, callback=lambda r, g, b: (b, r, g, (r + g + b) / 2)
         )
-        self.assertEqual(tuple(lut.size), (5, 5, 5))
-        self.assertEqual(lut.name, "Color 3D LUT")
+        assert tuple(lut.size) == (5, 5, 5)
+        assert lut.name == "Color 3D LUT"
         # fmt: off
-        self.assertEqual(lut.table[:24], [
+        assert lut.table[:24] == [
             0.0, 0.0, 0.0, 0.0,  0.0, 0.25, 0.0, 0.125,  0.0, 0.5, 0.0, 0.25,
             0.0, 0.75, 0.0, 0.375,  0.0, 1.0, 0.0, 0.5,  0.0, 0.0, 0.25, 0.125
-        ])
+        ]
         # fmt: on
 
     def test_apply(self):
@@ -445,7 +447,7 @@ class TestGenerateColorLut3D(PillowTestCase):
         im = Image.merge(
             "RGB", [g, g.transpose(Image.ROTATE_90), g.transpose(Image.ROTATE_180)]
         )
-        self.assertEqual(im, im.filter(lut))
+        assert im == im.filter(lut)
 
 
 class TestTransformColorLut3D(PillowTestCase):
@@ -461,7 +463,7 @@ class TestTransformColorLut3D(PillowTestCase):
         with self.assertRaisesRegex(ValueError, "should have either channels"):
             source.transform(lambda r, g, b: (r, g, b, 1))
 
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             source.transform(lambda r, g, b, a: (r, g, b))
 
     def test_target_mode(self):
@@ -470,31 +472,29 @@ class TestTransformColorLut3D(PillowTestCase):
         )
 
         lut = source.transform(lambda r, g, b: (r, g, b))
-        self.assertEqual(lut.mode, "HSV")
+        assert lut.mode == "HSV"
 
         lut = source.transform(lambda r, g, b: (r, g, b), target_mode="RGB")
-        self.assertEqual(lut.mode, "RGB")
+        assert lut.mode == "RGB"
 
     def test_3_to_3_channels(self):
         source = ImageFilter.Color3DLUT.generate((3, 4, 5), lambda r, g, b: (r, g, b))
         lut = source.transform(lambda r, g, b: (r * r, g * g, b * b))
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
-        self.assertEqual(
-            lut.table[0:10], [0.0, 0.0, 0.0, 0.25, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0]
-        )
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) == len(source.table)
+        assert lut.table != source.table
+        assert lut.table[0:10] == [0.0, 0.0, 0.0, 0.25, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0]
 
     def test_3_to_4_channels(self):
         source = ImageFilter.Color3DLUT.generate((6, 5, 4), lambda r, g, b: (r, g, b))
         lut = source.transform(lambda r, g, b: (r * r, g * g, b * b, 1), channels=4)
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertNotEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) != len(source.table)
+        assert lut.table != source.table
         # fmt: off
-        self.assertEqual(lut.table[0:16], [
+        assert lut.table[0:16] == [
             0.0, 0.0, 0.0, 1,  0.2**2, 0.0, 0.0, 1,
-            0.4**2, 0.0, 0.0, 1,  0.6**2, 0.0, 0.0, 1])
+            0.4**2, 0.0, 0.0, 1,  0.6**2, 0.0, 0.0, 1]
         # fmt: on
 
     def test_4_to_3_channels(self):
@@ -504,13 +504,13 @@ class TestTransformColorLut3D(PillowTestCase):
         lut = source.transform(
             lambda r, g, b, a: (a - r * r, a - g * g, a - b * b), channels=3
         )
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertNotEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) != len(source.table)
+        assert lut.table != source.table
         # fmt: off
-        self.assertEqual(lut.table[0:18], [
+        assert lut.table[0:18] == [
             1.0, 1.0, 1.0,  0.75, 1.0, 1.0,  0.0, 1.0, 1.0,
-            1.0, 0.96, 1.0,  0.75, 0.96, 1.0,  0.0, 0.96, 1.0])
+            1.0, 0.96, 1.0,  0.75, 0.96, 1.0,  0.0, 0.96, 1.0]
         # fmt: on
 
     def test_4_to_4_channels(self):
@@ -518,13 +518,13 @@ class TestTransformColorLut3D(PillowTestCase):
             (6, 5, 4), lambda r, g, b: (r, g, b, 1), channels=4
         )
         lut = source.transform(lambda r, g, b, a: (r * r, g * g, b * b, a - 0.5))
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) == len(source.table)
+        assert lut.table != source.table
         # fmt: off
-        self.assertEqual(lut.table[0:16], [
+        assert lut.table[0:16] == [
             0.0, 0.0, 0.0, 0.5,  0.2**2, 0.0, 0.0, 0.5,
-            0.4**2, 0.0, 0.0, 0.5,  0.6**2, 0.0, 0.0, 0.5])
+            0.4**2, 0.0, 0.0, 0.5,  0.6**2, 0.0, 0.0, 0.5]
         # fmt: on
 
     def test_with_normals_3_channels(self):
@@ -534,13 +534,13 @@ class TestTransformColorLut3D(PillowTestCase):
         lut = source.transform(
             lambda nr, ng, nb, r, g, b: (nr - r, ng - g, nb - b), with_normals=True
         )
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) == len(source.table)
+        assert lut.table != source.table
         # fmt: off
-        self.assertEqual(lut.table[0:18], [
+        assert lut.table[0:18] == [
             0.0, 0.0, 0.0,  0.16, 0.0, 0.0,  0.24, 0.0, 0.0,
-            0.24, 0.0, 0.0,  0.8 - (0.8**2), 0, 0,  0, 0, 0])
+            0.24, 0.0, 0.0,  0.8 - (0.8**2), 0, 0,  0, 0, 0]
         # fmt: on
 
     def test_with_normals_4_channels(self):
@@ -551,11 +551,11 @@ class TestTransformColorLut3D(PillowTestCase):
             lambda nr, ng, nb, r, g, b, a: (nr - r, ng - g, nb - b, a - 0.5),
             with_normals=True,
         )
-        self.assertEqual(tuple(lut.size), tuple(source.size))
-        self.assertEqual(len(lut.table), len(source.table))
-        self.assertNotEqual(lut.table, source.table)
+        assert tuple(lut.size) == tuple(source.size)
+        assert len(lut.table) == len(source.table)
+        assert lut.table != source.table
         # fmt: off
-        self.assertEqual(lut.table[0:16], [
+        assert lut.table[0:16] == [
             0.0, 0.0, 0.0, 0.5,  0.25, 0.0, 0.0, 0.5,
-            0.0, 0.0, 0.0, 0.5,  0.0, 0.16, 0.0, 0.5])
+            0.0, 0.0, 0.0, 0.5,  0.0, 0.16, 0.0, 0.5]
         # fmt: on

Tests/test_core_resources.py

@@ -43,38 +43,44 @@ class TestCoreMemory(PillowTestCase):
     def test_get_alignment(self):
         alignment = Image.core.get_alignment()
 
-        self.assertGreater(alignment, 0)
+        assert alignment > 0
 
     def test_set_alignment(self):
         for i in [1, 2, 4, 8, 16, 32]:
             Image.core.set_alignment(i)
             alignment = Image.core.get_alignment()
-            self.assertEqual(alignment, i)
+            assert alignment == i
 
             # Try to construct new image
             Image.new("RGB", (10, 10))
 
-        self.assertRaises(ValueError, Image.core.set_alignment, 0)
-        self.assertRaises(ValueError, Image.core.set_alignment, -1)
-        self.assertRaises(ValueError, Image.core.set_alignment, 3)
+        with pytest.raises(ValueError):
+            Image.core.set_alignment(0)
+        with pytest.raises(ValueError):
+            Image.core.set_alignment(-1)
+        with pytest.raises(ValueError):
+            Image.core.set_alignment(3)
 
     def test_get_block_size(self):
         block_size = Image.core.get_block_size()
 
-        self.assertGreaterEqual(block_size, 4096)
+        assert block_size >= 4096
 
     def test_set_block_size(self):
         for i in [4096, 2 * 4096, 3 * 4096]:
             Image.core.set_block_size(i)
             block_size = Image.core.get_block_size()
-            self.assertEqual(block_size, i)
+            assert block_size == i
 
             # Try to construct new image
             Image.new("RGB", (10, 10))
 
-        self.assertRaises(ValueError, Image.core.set_block_size, 0)
-        self.assertRaises(ValueError, Image.core.set_block_size, -1)
-        self.assertRaises(ValueError, Image.core.set_block_size, 4000)
+        with pytest.raises(ValueError):
+            Image.core.set_block_size(0)
+        with pytest.raises(ValueError):
+            Image.core.set_block_size(-1)
+        with pytest.raises(ValueError):
+            Image.core.set_block_size(4000)
 
     def test_set_block_size_stats(self):
         Image.core.reset_stats()
@@ -83,28 +89,30 @@ class TestCoreMemory(PillowTestCase):
         Image.new("RGB", (256, 256))
 
         stats = Image.core.get_stats()
-        self.assertGreaterEqual(stats["new_count"], 1)
-        self.assertGreaterEqual(stats["allocated_blocks"], 64)
+        assert stats["new_count"] >= 1
+        assert stats["allocated_blocks"] >= 64
         if not is_pypy():
-            self.assertGreaterEqual(stats["freed_blocks"], 64)
+            assert stats["freed_blocks"] >= 64
 
     def test_get_blocks_max(self):
         blocks_max = Image.core.get_blocks_max()
 
-        self.assertGreaterEqual(blocks_max, 0)
+        assert blocks_max >= 0
 
     def test_set_blocks_max(self):
         for i in [0, 1, 10]:
             Image.core.set_blocks_max(i)
             blocks_max = Image.core.get_blocks_max()
-            self.assertEqual(blocks_max, i)
+            assert blocks_max == i
 
             # Try to construct new image
             Image.new("RGB", (10, 10))
 
-        self.assertRaises(ValueError, Image.core.set_blocks_max, -1)
+        with pytest.raises(ValueError):
+            Image.core.set_blocks_max(-1)
         if sys.maxsize < 2 ** 32:
-            self.assertRaises(ValueError, Image.core.set_blocks_max, 2 ** 29)
+            with pytest.raises(ValueError):
+                Image.core.set_blocks_max(2 ** 29)
 
     @unittest.skipIf(is_pypy(), "images are not collected")
     def test_set_blocks_max_stats(self):
@@ -115,11 +123,11 @@ class TestCoreMemory(PillowTestCase):
         Image.new("RGB", (256, 256))
 
         stats = Image.core.get_stats()
-        self.assertGreaterEqual(stats["new_count"], 2)
-        self.assertGreaterEqual(stats["allocated_blocks"], 64)
-        self.assertGreaterEqual(stats["reused_blocks"], 64)
-        self.assertEqual(stats["freed_blocks"], 0)
-        self.assertEqual(stats["blocks_cached"], 64)
+        assert stats["new_count"] >= 2
+        assert stats["allocated_blocks"] >= 64
+        assert stats["reused_blocks"] >= 64
+        assert stats["freed_blocks"] == 0
+        assert stats["blocks_cached"] == 64
 
     @unittest.skipIf(is_pypy(), "images are not collected")
     def test_clear_cache_stats(self):
@@ -133,11 +141,11 @@ class TestCoreMemory(PillowTestCase):
         Image.core.clear_cache(16)
 
         stats = Image.core.get_stats()
-        self.assertGreaterEqual(stats["new_count"], 2)
-        self.assertGreaterEqual(stats["allocated_blocks"], 64)
-        self.assertGreaterEqual(stats["reused_blocks"], 64)
-        self.assertGreaterEqual(stats["freed_blocks"], 48)
-        self.assertEqual(stats["blocks_cached"], 16)
+        assert stats["new_count"] >= 2
+        assert stats["allocated_blocks"] >= 64
+        assert stats["reused_blocks"] >= 64
+        assert stats["freed_blocks"] >= 48
+        assert stats["blocks_cached"] == 16
 
     def test_large_images(self):
         Image.core.reset_stats()
@@ -147,12 +155,12 @@ class TestCoreMemory(PillowTestCase):
         Image.core.clear_cache()
 
         stats = Image.core.get_stats()
-        self.assertGreaterEqual(stats["new_count"], 1)
-        self.assertGreaterEqual(stats["allocated_blocks"], 16)
-        self.assertGreaterEqual(stats["reused_blocks"], 0)
-        self.assertEqual(stats["blocks_cached"], 0)
+        assert stats["new_count"] >= 1
+        assert stats["allocated_blocks"] >= 16
+        assert stats["reused_blocks"] >= 0
+        assert stats["blocks_cached"] == 0
         if not is_pypy():
-            self.assertGreaterEqual(stats["freed_blocks"], 16)
+            assert stats["freed_blocks"] >= 16
 
 
 class TestEnvVars(PillowTestCase):
@@ -165,9 +173,9 @@ class TestEnvVars(PillowTestCase):
 
     def test_units(self):
         Image._apply_env_variables({"PILLOW_BLOCKS_MAX": "2K"})
-        self.assertEqual(Image.core.get_blocks_max(), 2 * 1024)
+        assert Image.core.get_blocks_max() == 2 * 1024
         Image._apply_env_variables({"PILLOW_BLOCK_SIZE": "2m"})
-        self.assertEqual(Image.core.get_block_size(), 2 * 1024 * 1024)
+        assert Image.core.get_block_size() == 2 * 1024 * 1024
 
     def test_warnings(self):
         pytest.warns(

Tests/test_file_eps.py

@@ -1,6 +1,7 @@
 import io
 import unittest
 
+import pytest
 from PIL import EpsImagePlugin, Image, features
 
 from .helper import PillowTestCase, assert_image_similar, hopper, skip_unless_feature
@@ -28,44 +29,45 @@ class TestFileEps(PillowTestCase):
         # Regular scale
         with Image.open(file1) as image1:
             image1.load()
-            self.assertEqual(image1.mode, "RGB")
-            self.assertEqual(image1.size, (460, 352))
-            self.assertEqual(image1.format, "EPS")
+            assert image1.mode == "RGB"
+            assert image1.size == (460, 352)
+            assert image1.format == "EPS"
 
         with Image.open(file2) as image2:
             image2.load()
-            self.assertEqual(image2.mode, "RGB")
-            self.assertEqual(image2.size, (360, 252))
-            self.assertEqual(image2.format, "EPS")
+            assert image2.mode == "RGB"
+            assert image2.size == (360, 252)
+            assert image2.format == "EPS"
 
         # Double scale
         with Image.open(file1) as image1_scale2:
             image1_scale2.load(scale=2)
-            self.assertEqual(image1_scale2.mode, "RGB")
-            self.assertEqual(image1_scale2.size, (920, 704))
-            self.assertEqual(image1_scale2.format, "EPS")
+            assert image1_scale2.mode == "RGB"
+            assert image1_scale2.size == (920, 704)
+            assert image1_scale2.format == "EPS"
 
         with Image.open(file2) as image2_scale2:
             image2_scale2.load(scale=2)
-            self.assertEqual(image2_scale2.mode, "RGB")
-            self.assertEqual(image2_scale2.size, (720, 504))
-            self.assertEqual(image2_scale2.format, "EPS")
+            assert image2_scale2.mode == "RGB"
+            assert image2_scale2.size == (720, 504)
+            assert image2_scale2.format == "EPS"
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, EpsImagePlugin.EpsImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            EpsImagePlugin.EpsImageFile(invalid_file)
 
     @unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
     def test_cmyk(self):
         with Image.open("Tests/images/pil_sample_cmyk.eps") as cmyk_image:
 
-            self.assertEqual(cmyk_image.mode, "CMYK")
-            self.assertEqual(cmyk_image.size, (100, 100))
-            self.assertEqual(cmyk_image.format, "EPS")
+            assert cmyk_image.mode == "CMYK"
+            assert cmyk_image.size == (100, 100)
+            assert cmyk_image.format == "EPS"
 
             cmyk_image.load()
-            self.assertEqual(cmyk_image.mode, "RGB")
+            assert cmyk_image.mode == "RGB"
 
             if features.check("jpg"):
                 with Image.open("Tests/images/pil_sample_rgb.jpg") as target:
@@ -111,7 +113,8 @@ class TestFileEps(PillowTestCase):
     def test_image_mode_not_supported(self):
         im = hopper("RGBA")
         tmpfile = self.tempfile("temp.eps")
-        self.assertRaises(ValueError, im.save, tmpfile)
+        with pytest.raises(ValueError):
+            im.save(tmpfile)
 
     @unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
     @skip_unless_feature("zlib")
@@ -162,7 +165,7 @@ class TestFileEps(PillowTestCase):
             with Image.open(fn) as im:
                 new_size = (100, 100)
                 im = im.resize(new_size)
-                self.assertEqual(im.size, new_size)
+                assert im.size == new_size
 
     @unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
     def test_thumbnail(self):
@@ -173,7 +176,7 @@ class TestFileEps(PillowTestCase):
             with Image.open(file1) as im:
                 new_size = (100, 100)
                 im.thumbnail(new_size)
-                self.assertEqual(max(im.size), max(new_size))
+                assert max(im.size) == max(new_size)
 
     def test_read_binary_preview(self):
         # Issue 302
@@ -185,10 +188,10 @@ class TestFileEps(PillowTestCase):
         ending = "Failure with line ending: %s" % (
             "".join("%s" % ord(s) for s in ending)
         )
-        self.assertEqual(t.readline().strip("\r\n"), "something", ending)
-        self.assertEqual(t.readline().strip("\r\n"), "else", ending)
-        self.assertEqual(t.readline().strip("\r\n"), "baz", ending)
-        self.assertEqual(t.readline().strip("\r\n"), "bif", ending)
+        assert t.readline().strip("\r\n") == "something", ending
+        assert t.readline().strip("\r\n") == "else", ending
+        assert t.readline().strip("\r\n") == "baz", ending
+        assert t.readline().strip("\r\n") == "bif", ending
 
     def _test_readline_io_psfile(self, test_string, ending):
         f = io.BytesIO(test_string.encode("latin-1"))
@@ -228,7 +231,7 @@ class TestFileEps(PillowTestCase):
         # Act / Assert
         for filename in FILES:
             with Image.open(filename) as img:
-                self.assertEqual(img.mode, "RGB")
+                assert img.mode == "RGB"
 
     @unittest.skipUnless(HAS_GHOSTSCRIPT, "Ghostscript not available")
     def test_emptyline(self):
@@ -237,6 +240,6 @@ class TestFileEps(PillowTestCase):
 
         with Image.open(emptyline_file) as image:
             image.load()
-        self.assertEqual(image.mode, "RGB")
-        self.assertEqual(image.size, (460, 352))
-        self.assertEqual(image.format, "EPS")
+        assert image.mode == "RGB"
+        assert image.size == (460, 352)
+        assert image.format == "EPS"

Tests/test_file_gif.py

@@ -24,10 +24,10 @@ class TestFileGif(PillowTestCase):
     def test_sanity(self):
         with Image.open(TEST_GIF) as im:
             im.load()
-            self.assertEqual(im.mode, "P")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "GIF")
-            self.assertEqual(im.info["version"], b"GIF89a")
+            assert im.mode == "P"
+            assert im.size == (128, 128)
+            assert im.format == "GIF"
+            assert im.info["version"] == b"GIF89a"
 
     @unittest.skipIf(is_pypy(), "Requires CPython")
     def test_unclosed_file(self):
@@ -55,7 +55,8 @@ class TestFileGif(PillowTestCase):
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, GifImagePlugin.GifImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            GifImagePlugin.GifImageFile(invalid_file)
 
     def test_optimize(self):
         def test_grayscale(optimize):
@@ -70,10 +71,10 @@ class TestFileGif(PillowTestCase):
             im.save(test_file, "GIF", optimize=optimize)
             return len(test_file.getvalue())
 
-        self.assertEqual(test_grayscale(0), 800)
-        self.assertEqual(test_grayscale(1), 44)
-        self.assertEqual(test_bilevel(0), 800)
-        self.assertEqual(test_bilevel(1), 800)
+        assert test_grayscale(0) == 800
+        assert test_grayscale(1) == 44
+        assert test_bilevel(0) == 800
+        assert test_bilevel(1) == 800
 
     def test_optimize_correctness(self):
         # 256 color Palette image, posterize to > 128 and < 128 levels
@@ -94,7 +95,7 @@ class TestFileGif(PillowTestCase):
                 palette_length = max(
                     i + 1 for i, v in enumerate(reloaded.histogram()) if v
                 )
-                self.assertEqual(expected_palette_length, palette_length)
+                assert expected_palette_length == palette_length
 
                 assert_image_equal(im.convert("RGB"), reloaded.convert("RGB"))
 
@@ -117,7 +118,7 @@ class TestFileGif(PillowTestCase):
         im = Image.frombytes("L", (16, 16), bytes(range(256)))
         test_file = BytesIO()
         im.save(test_file, "GIF", optimize=True)
-        self.assertEqual(im.mode, "L")
+        assert im.mode == "L"
 
     def test_roundtrip(self):
         out = self.tempfile("temp.gif")
@@ -153,7 +154,7 @@ class TestFileGif(PillowTestCase):
             im.save(out, save_all=True)
         with Image.open(out) as reread:
 
-            self.assertEqual(reread.n_frames, 5)
+            assert reread.n_frames == 5
 
     def test_headers_saving_for_animated_gifs(self):
         important_headers = ["background", "version", "duration", "loop"]
@@ -167,7 +168,7 @@ class TestFileGif(PillowTestCase):
         with Image.open(out) as reread:
 
             for header in important_headers:
-                self.assertEqual(info[header], reread.info[header])
+                assert info[header] == reread.info[header]
 
     def test_palette_handling(self):
         # see https://github.com/python-pillow/Pillow/issues/513
@@ -237,7 +238,7 @@ class TestFileGif(PillowTestCase):
                     framecount += 1
                     img.seek(img.tell() + 1)
             except EOFError:
-                self.assertEqual(framecount, 5)
+                assert framecount == 5
 
     def test_seek_info(self):
         with Image.open("Tests/images/iss634.gif") as im:
@@ -246,7 +247,7 @@ class TestFileGif(PillowTestCase):
             im.seek(1)
             im.seek(0)
 
-            self.assertEqual(im.info, info)
+            assert im.info == info
 
     def test_seek_rewind(self):
         with Image.open("Tests/images/iss634.gif") as im:
@@ -261,20 +262,21 @@ class TestFileGif(PillowTestCase):
         for path, n_frames in [[TEST_GIF, 1], ["Tests/images/iss634.gif", 42]]:
             # Test is_animated before n_frames
             with Image.open(path) as im:
-                self.assertEqual(im.is_animated, n_frames != 1)
+                assert im.is_animated == (n_frames != 1)
 
             # Test is_animated after n_frames
             with Image.open(path) as im:
-                self.assertEqual(im.n_frames, n_frames)
-                self.assertEqual(im.is_animated, n_frames != 1)
+                assert im.n_frames == n_frames
+                assert im.is_animated == (n_frames != 1)
 
     def test_eoferror(self):
         with Image.open(TEST_GIF) as im:
             n_frames = im.n_frames
 
             # Test seeking past the last frame
-            self.assertRaises(EOFError, im.seek, n_frames)
-            self.assertLess(im.tell(), n_frames)
+            with pytest.raises(EOFError):
+                im.seek(n_frames)
+            assert im.tell() < n_frames
 
             # Test that seeking to the last frame does not raise an error
             im.seek(n_frames - 1)
@@ -284,7 +286,7 @@ class TestFileGif(PillowTestCase):
             try:
                 while True:
                     img.seek(img.tell() + 1)
-                    self.assertEqual(img.disposal_method, 1)
+                    assert img.disposal_method == 1
             except EOFError:
                 pass
 
@@ -293,7 +295,7 @@ class TestFileGif(PillowTestCase):
             try:
                 while True:
                     img.seek(img.tell() + 1)
-                    self.assertEqual(img.disposal_method, 2)
+                    assert img.disposal_method == 2
             except EOFError:
                 pass
 
@@ -302,7 +304,7 @@ class TestFileGif(PillowTestCase):
             try:
                 while True:
                     img.seek(img.tell() + 1)
-                    self.assertEqual(img.disposal_method, 3)
+                    assert img.disposal_method == 3
             except EOFError:
                 pass
 
@@ -320,7 +322,7 @@ class TestFileGif(PillowTestCase):
             with Image.open(out) as img:
                 for _ in range(2):
                     img.seek(img.tell() + 1)
-                    self.assertEqual(img.disposal_method, method)
+                    assert img.disposal_method == method
 
         # check per frame disposal
         im_list[0].save(
@@ -334,7 +336,7 @@ class TestFileGif(PillowTestCase):
 
             for i in range(2):
                 img.seek(img.tell() + 1)
-                self.assertEqual(img.disposal_method, i + 1)
+                assert img.disposal_method == i + 1
 
     def test_dispose2_palette(self):
         out = self.tempfile("temp.gif")
@@ -360,10 +362,10 @@ class TestFileGif(PillowTestCase):
                 rgb_img = img.convert("RGB")
 
                 # Check top left pixel matches background
-                self.assertEqual(rgb_img.getpixel((0, 0)), (255, 0, 0))
+                assert rgb_img.getpixel((0, 0)) == (255, 0, 0)
 
                 # Center remains red every frame
-                self.assertEqual(rgb_img.getpixel((50, 50)), circle)
+                assert rgb_img.getpixel((50, 50)) == circle
 
     def test_dispose2_diff(self):
         out = self.tempfile("temp.gif")
@@ -398,13 +400,13 @@ class TestFileGif(PillowTestCase):
                 rgb_img = img.convert("RGBA")
 
                 # Check left circle is correct colour
-                self.assertEqual(rgb_img.getpixel((20, 50)), colours[0])
+                assert rgb_img.getpixel((20, 50)) == colours[0]
 
                 # Check right circle is correct colour
-                self.assertEqual(rgb_img.getpixel((80, 50)), colours[1])
+                assert rgb_img.getpixel((80, 50)) == colours[1]
 
                 # Check BG is correct colour
-                self.assertEqual(rgb_img.getpixel((1, 1)), (255, 255, 255, 0))
+                assert rgb_img.getpixel((1, 1)) == (255, 255, 255, 0)
 
     def test_dispose2_background(self):
         out = self.tempfile("temp.gif")
@@ -429,7 +431,7 @@ class TestFileGif(PillowTestCase):
 
         with Image.open(out) as im:
             im.seek(1)
-            self.assertEqual(im.getpixel((0, 0)), 0)
+            assert im.getpixel((0, 0)) == 0
 
     def test_iss634(self):
         with Image.open("Tests/images/iss634.gif") as img:
@@ -437,7 +439,7 @@ class TestFileGif(PillowTestCase):
             img.seek(img.tell() + 1)
             # all transparent pixels should be replaced with the color from the
             # first frame
-            self.assertEqual(img.histogram()[img.info["transparency"]], 0)
+            assert img.histogram()[img.info["transparency"]] == 0
 
     def test_duration(self):
         duration = 1000
@@ -450,7 +452,7 @@ class TestFileGif(PillowTestCase):
         im.save(out, duration=duration)
 
         with Image.open(out) as reread:
-            self.assertEqual(reread.info["duration"], duration)
+            assert reread.info["duration"] == duration
 
     def test_multiple_duration(self):
         duration_list = [1000, 2000, 3000]
@@ -469,7 +471,7 @@ class TestFileGif(PillowTestCase):
         with Image.open(out) as reread:
 
             for duration in duration_list:
-                self.assertEqual(reread.info["duration"], duration)
+                assert reread.info["duration"] == duration
                 try:
                     reread.seek(reread.tell() + 1)
                 except EOFError:
@@ -482,7 +484,7 @@ class TestFileGif(PillowTestCase):
         with Image.open(out) as reread:
 
             for duration in duration_list:
-                self.assertEqual(reread.info["duration"], duration)
+                assert reread.info["duration"] == duration
                 try:
                     reread.seek(reread.tell() + 1)
                 except EOFError:
@@ -506,10 +508,10 @@ class TestFileGif(PillowTestCase):
         with Image.open(out) as reread:
 
             # Assert that the first three frames were combined
-            self.assertEqual(reread.n_frames, 2)
+            assert reread.n_frames == 2
 
             # Assert that the new duration is the total of the identical frames
-            self.assertEqual(reread.info["duration"], 4500)
+            assert reread.info["duration"] == 4500
 
     def test_identical_frames_to_single_frame(self):
         for duration in ([1000, 1500, 2000, 4000], (1000, 1500, 2000, 4000), 8500):
@@ -525,10 +527,10 @@ class TestFileGif(PillowTestCase):
             )
             with Image.open(out) as reread:
                 # Assert that all frames were combined
-                self.assertEqual(reread.n_frames, 1)
+                assert reread.n_frames == 1
 
                 # Assert that the new duration is the total of the identical frames
-                self.assertEqual(reread.info["duration"], 8500)
+                assert reread.info["duration"] == 8500
 
     def test_number_of_loops(self):
         number_of_loops = 2
@@ -538,7 +540,7 @@ class TestFileGif(PillowTestCase):
         im.save(out, loop=number_of_loops)
         with Image.open(out) as reread:
 
-            self.assertEqual(reread.info["loop"], number_of_loops)
+            assert reread.info["loop"] == number_of_loops
 
     def test_background(self):
         out = self.tempfile("temp.gif")
@@ -547,30 +549,28 @@ class TestFileGif(PillowTestCase):
         im.save(out)
         with Image.open(out) as reread:
 
-            self.assertEqual(reread.info["background"], im.info["background"])
+            assert reread.info["background"] == im.info["background"]
 
         if features.check("webp") and features.check("webp_anim"):
             with Image.open("Tests/images/hopper.webp") as im:
-                self.assertIsInstance(im.info["background"], tuple)
+                assert isinstance(im.info["background"], tuple)
                 im.save(out)
 
     def test_comment(self):
         with Image.open(TEST_GIF) as im:
-            self.assertEqual(
-                im.info["comment"], b"File written by Adobe Photoshop\xa8 4.0"
-            )
+            assert im.info["comment"] == b"File written by Adobe Photoshop\xa8 4.0"
 
         out = self.tempfile("temp.gif")
         im = Image.new("L", (100, 100), "#000")
         im.info["comment"] = b"Test comment text"
         im.save(out)
         with Image.open(out) as reread:
-            self.assertEqual(reread.info["comment"], im.info["comment"])
+            assert reread.info["comment"] == im.info["comment"]
 
         im.info["comment"] = "Test comment text"
         im.save(out)
         with Image.open(out) as reread:
-            self.assertEqual(reread.info["comment"], im.info["comment"].encode())
+            assert reread.info["comment"] == im.info["comment"].encode()
 
     def test_comment_over_255(self):
         out = self.tempfile("temp.gif")
@@ -582,7 +582,7 @@ class TestFileGif(PillowTestCase):
         im.save(out)
         with Image.open(out) as reread:
 
-            self.assertEqual(reread.info["comment"], comment)
+            assert reread.info["comment"] == comment
 
     def test_zero_comment_subblocks(self):
         with Image.open("Tests/images/hopper_zero_comment_subblocks.gif") as im:
@@ -595,7 +595,7 @@ class TestFileGif(PillowTestCase):
         def assertVersionAfterSave(im, version):
             im.save(out)
             with Image.open(out) as reread:
-                self.assertEqual(reread.info["version"], version)
+                assert reread.info["version"] == version
 
         # Test that GIF87a is used by default
         im = Image.new("L", (100, 100), "#000")
@@ -627,7 +627,7 @@ class TestFileGif(PillowTestCase):
         im.copy().save(out, save_all=True, append_images=ims)
 
         with Image.open(out) as reread:
-            self.assertEqual(reread.n_frames, 3)
+            assert reread.n_frames == 3
 
         # Tests appending using a generator
         def imGenerator(ims):
@@ -636,7 +636,7 @@ class TestFileGif(PillowTestCase):
         im.save(out, save_all=True, append_images=imGenerator(ims))
 
         with Image.open(out) as reread:
-            self.assertEqual(reread.n_frames, 3)
+            assert reread.n_frames == 3
 
         # Tests appending single and multiple frame images
         with Image.open("Tests/images/dispose_none.gif") as im:
@@ -644,7 +644,7 @@ class TestFileGif(PillowTestCase):
                 im.save(out, save_all=True, append_images=[im2])
 
         with Image.open(out) as reread:
-            self.assertEqual(reread.n_frames, 10)
+            assert reread.n_frames == 10
 
     def test_transparent_optimize(self):
         # from issue #2195, if the transparent color is incorrectly
@@ -664,7 +664,7 @@ class TestFileGif(PillowTestCase):
         im.save(out, transparency=253)
         with Image.open(out) as reloaded:
 
-            self.assertEqual(reloaded.info["transparency"], 253)
+            assert reloaded.info["transparency"] == 253
 
     def test_rgb_transparency(self):
         out = self.tempfile("temp.gif")
@@ -675,7 +675,7 @@ class TestFileGif(PillowTestCase):
         pytest.warns(UserWarning, im.save, out)
 
         with Image.open(out) as reloaded:
-            self.assertNotIn("transparency", reloaded.info)
+            assert "transparency" not in reloaded.info
 
         # Multiple frames
         im = Image.new("RGB", (1, 1))
@@ -684,7 +684,7 @@ class TestFileGif(PillowTestCase):
         pytest.warns(UserWarning, im.save, out, save_all=True, append_images=ims)
 
         with Image.open(out) as reloaded:
-            self.assertNotIn("transparency", reloaded.info)
+            assert "transparency" not in reloaded.info
 
     def test_bbox(self):
         out = self.tempfile("temp.gif")
@@ -694,7 +694,7 @@ class TestFileGif(PillowTestCase):
         im.save(out, save_all=True, append_images=ims)
 
         with Image.open(out) as reread:
-            self.assertEqual(reread.n_frames, 2)
+            assert reread.n_frames == 2
 
     def test_palette_save_L(self):
         # generate an L mode image with a separate palette
@@ -772,20 +772,20 @@ class TestFileGif(PillowTestCase):
             with open("Tests/images/gif_header_data.pkl", "rb") as f:
                 (h_target, d_target) = pickle.load(f)
 
-            self.assertEqual(h, h_target)
-            self.assertEqual(d, d_target)
+            assert h == h_target
+            assert d == d_target
         finally:
             GifImagePlugin._FORCE_OPTIMIZE = False
 
     def test_lzw_bits(self):
         # see https://github.com/python-pillow/Pillow/issues/2811
         with Image.open("Tests/images/issue_2811.gif") as im:
-            self.assertEqual(im.tile[0][3][0], 11)  # LZW bits
+            assert im.tile[0][3][0] == 11  # LZW bits
             # codec error prepatch
             im.load()
 
     def test_extents(self):
         with Image.open("Tests/images/test_extents.gif") as im:
-            self.assertEqual(im.size, (100, 100))
+            assert im.size == (100, 100)
             im.seek(1)
-            self.assertEqual(im.size, (150, 150))
+            assert im.size == (150, 150)

Tests/test_file_icns.py

@@ -22,9 +22,9 @@ class TestFileIcns(PillowTestCase):
             # Assert that there is no unclosed file warning
             pytest.warns(None, im.load)
 
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (1024, 1024))
-            self.assertEqual(im.format, "ICNS")
+            assert im.mode == "RGBA"
+            assert im.size == (1024, 1024)
+            assert im.format == "ICNS"
 
     @unittest.skipIf(sys.platform != "darwin", "requires macOS")
     def test_save(self):
@@ -34,9 +34,9 @@ class TestFileIcns(PillowTestCase):
             im.save(temp_file)
 
         with Image.open(temp_file) as reread:
-            self.assertEqual(reread.mode, "RGBA")
-            self.assertEqual(reread.size, (1024, 1024))
-            self.assertEqual(reread.format, "ICNS")
+            assert reread.mode == "RGBA"
+            assert reread.size == (1024, 1024)
+            assert reread.format == "ICNS"
 
     @unittest.skipIf(sys.platform != "darwin", "requires macOS")
     def test_save_append_images(self):
@@ -63,11 +63,11 @@ class TestFileIcns(PillowTestCase):
                 hr = h * r
                 im.size = (w, h, r)
                 im.load()
-                self.assertEqual(im.mode, "RGBA")
-                self.assertEqual(im.size, (wr, hr))
+                assert im.mode == "RGBA"
+                assert im.size == (wr, hr)
 
             # Check that we cannot load an incorrect size
-            with self.assertRaises(ValueError):
+            with pytest.raises(ValueError):
                 im.size = (1, 1)
 
     def test_older_icon(self):
@@ -80,8 +80,8 @@ class TestFileIcns(PillowTestCase):
                 with Image.open("Tests/images/pillow2.icns") as im2:
                     im2.size = (w, h, r)
                     im2.load()
-                    self.assertEqual(im2.mode, "RGBA")
-                    self.assertEqual(im2.size, (wr, hr))
+                    assert im2.mode == "RGBA"
+                    assert im2.size == (wr, hr)
 
     def test_jp2_icon(self):
         # This icon was made by using Uli Kusterer's oldiconutil to replace
@@ -101,21 +101,22 @@ class TestFileIcns(PillowTestCase):
                 with Image.open("Tests/images/pillow3.icns") as im2:
                     im2.size = (w, h, r)
                     im2.load()
-                    self.assertEqual(im2.mode, "RGBA")
-                    self.assertEqual(im2.size, (wr, hr))
+                    assert im2.mode == "RGBA"
+                    assert im2.size == (wr, hr)
 
     def test_getimage(self):
         with open(TEST_FILE, "rb") as fp:
             icns_file = IcnsImagePlugin.IcnsFile(fp)
 
             im = icns_file.getimage()
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (1024, 1024))
+            assert im.mode == "RGBA"
+            assert im.size == (1024, 1024)
 
             im = icns_file.getimage((512, 512))
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (512, 512))
+            assert im.mode == "RGBA"
+            assert im.size == (512, 512)
 
     def test_not_an_icns_file(self):
         with io.BytesIO(b"invalid\n") as fp:
-            self.assertRaises(SyntaxError, IcnsImagePlugin.IcnsFile, fp)
+            with pytest.raises(SyntaxError):
+                IcnsImagePlugin.IcnsFile(fp)

Tests/test_file_ico.py

@@ -12,14 +12,15 @@ class TestFileIco(PillowTestCase):
     def test_sanity(self):
         with Image.open(TEST_ICO_FILE) as im:
             im.load()
-        self.assertEqual(im.mode, "RGBA")
-        self.assertEqual(im.size, (16, 16))
-        self.assertEqual(im.format, "ICO")
-        self.assertEqual(im.get_format_mimetype(), "image/x-icon")
+        assert im.mode == "RGBA"
+        assert im.size == (16, 16)
+        assert im.format == "ICO"
+        assert im.get_format_mimetype() == "image/x-icon"
 
     def test_invalid_file(self):
         with open("Tests/images/flower.jpg", "rb") as fp:
-            self.assertRaises(SyntaxError, IcoImagePlugin.IcoImageFile, fp)
+            with pytest.raises(SyntaxError):
+                IcoImagePlugin.IcoImageFile(fp)
 
     def test_save_to_bytes(self):
         output = io.BytesIO()
@@ -29,11 +30,11 @@ class TestFileIco(PillowTestCase):
         # the default image
         output.seek(0)
         with Image.open(output) as reloaded:
-            self.assertEqual(reloaded.info["sizes"], {(32, 32), (64, 64)})
+            assert reloaded.info["sizes"] == {(32, 32), (64, 64)}
 
-            self.assertEqual(im.mode, reloaded.mode)
-            self.assertEqual((64, 64), reloaded.size)
-            self.assertEqual(reloaded.format, "ICO")
+            assert im.mode == reloaded.mode
+            assert (64, 64) == reloaded.size
+            assert reloaded.format == "ICO"
             assert_image_equal(reloaded, hopper().resize((64, 64), Image.LANCZOS))
 
         # the other one
@@ -41,14 +42,14 @@ class TestFileIco(PillowTestCase):
         with Image.open(output) as reloaded:
             reloaded.size = (32, 32)
 
-            self.assertEqual(im.mode, reloaded.mode)
-            self.assertEqual((32, 32), reloaded.size)
-            self.assertEqual(reloaded.format, "ICO")
+            assert im.mode == reloaded.mode
+            assert (32, 32) == reloaded.size
+            assert reloaded.format == "ICO"
             assert_image_equal(reloaded, hopper().resize((32, 32), Image.LANCZOS))
 
     def test_incorrect_size(self):
         with Image.open(TEST_ICO_FILE) as im:
-            with self.assertRaises(ValueError):
+            with pytest.raises(ValueError):
                 im.size = (1, 1)
 
     def test_save_256x256(self):
@@ -62,7 +63,7 @@ class TestFileIco(PillowTestCase):
         with Image.open(outfile) as im_saved:
 
             # Assert
-            self.assertEqual(im_saved.size, (256, 256))
+            assert im_saved.size == (256, 256)
 
     def test_only_save_relevant_sizes(self):
         """Issue #2266 https://github.com/python-pillow/Pillow/issues/2266
@@ -77,16 +78,14 @@ class TestFileIco(PillowTestCase):
 
         with Image.open(outfile) as im_saved:
             # Assert
-            self.assertEqual(
-                im_saved.info["sizes"], {(16, 16), (24, 24), (32, 32), (48, 48)}
-            )
+            assert im_saved.info["sizes"] == {(16, 16), (24, 24), (32, 32), (48, 48)}
 
     def test_unexpected_size(self):
         # This image has been manually hexedited to state that it is 16x32
         # while the image within is still 16x16
         def open():
             with Image.open("Tests/images/hopper_unexpected.ico") as im:
-                self.assertEqual(im.size, (16, 16))
+                assert im.size == (16, 16)
 
         pytest.warns(UserWarning, open)
 

Tests/test_file_jpeg.py

@@ -46,21 +46,20 @@ class TestFileJpeg(PillowTestCase):
 
         with Image.open(TEST_FILE) as im:
             im.load()
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "JPEG")
-            self.assertEqual(im.get_format_mimetype(), "image/jpeg")
+            assert im.mode == "RGB"
+            assert im.size == (128, 128)
+            assert im.format == "JPEG"
+            assert im.get_format_mimetype() == "image/jpeg"
 
     def test_app(self):
         # Test APP/COM reader (@PIL135)
         with Image.open(TEST_FILE) as im:
-            self.assertEqual(
-                im.applist[0], ("APP0", b"JFIF\x00\x01\x01\x01\x00`\x00`\x00\x00")
+            assert im.applist[0] == ("APP0", b"JFIF\x00\x01\x01\x01\x00`\x00`\x00\x00")
+            assert im.applist[1] == (
+                "COM",
+                b"File written by Adobe Photoshop\xa8 4.0\x00",
             )
-            self.assertEqual(
-                im.applist[1], ("COM", b"File written by Adobe Photoshop\xa8 4.0\x00")
-            )
-            self.assertEqual(len(im.applist), 2)
+            assert len(im.applist) == 2
 
     def test_cmyk(self):
         # Test CMYK handling.  Thanks to Tim and Charlie for test data,
@@ -69,26 +68,26 @@ class TestFileJpeg(PillowTestCase):
         with Image.open(f) as im:
             # the source image has red pixels in the upper left corner.
             c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))]
-            self.assertEqual(c, 0.0)
-            self.assertGreater(m, 0.8)
-            self.assertGreater(y, 0.8)
-            self.assertEqual(k, 0.0)
+            assert c == 0.0
+            assert m > 0.8
+            assert y > 0.8
+            assert k == 0.0
             # the opposite corner is black
             c, m, y, k = [
                 x / 255.0 for x in im.getpixel((im.size[0] - 1, im.size[1] - 1))
             ]
-            self.assertGreater(k, 0.9)
+            assert k > 0.9
             # roundtrip, and check again
             im = self.roundtrip(im)
             c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))]
-            self.assertEqual(c, 0.0)
-            self.assertGreater(m, 0.8)
-            self.assertGreater(y, 0.8)
-            self.assertEqual(k, 0.0)
+            assert c == 0.0
+            assert m > 0.8
+            assert y > 0.8
+            assert k == 0.0
             c, m, y, k = [
                 x / 255.0 for x in im.getpixel((im.size[0] - 1, im.size[1] - 1))
             ]
-            self.assertGreater(k, 0.9)
+            assert k > 0.9
 
     def test_dpi(self):
         def test(xdpi, ydpi=None):
@@ -96,27 +95,27 @@ class TestFileJpeg(PillowTestCase):
                 im = self.roundtrip(im, dpi=(xdpi, ydpi or xdpi))
             return im.info.get("dpi")
 
-        self.assertEqual(test(72), (72, 72))
-        self.assertEqual(test(300), (300, 300))
-        self.assertEqual(test(100, 200), (100, 200))
-        self.assertIsNone(test(0))  # square pixels
+        assert test(72) == (72, 72)
+        assert test(300) == (300, 300)
+        assert test(100, 200) == (100, 200)
+        assert test(0) is None  # square pixels
 
     def test_icc(self):
         # Test ICC support
         with Image.open("Tests/images/rgb.jpg") as im1:
             icc_profile = im1.info["icc_profile"]
-            self.assertEqual(len(icc_profile), 3144)
+            assert len(icc_profile) == 3144
             # Roundtrip via physical file.
             f = self.tempfile("temp.jpg")
             im1.save(f, icc_profile=icc_profile)
         with Image.open(f) as im2:
-            self.assertEqual(im2.info.get("icc_profile"), icc_profile)
+            assert im2.info.get("icc_profile") == icc_profile
             # Roundtrip via memory buffer.
             im1 = self.roundtrip(hopper())
             im2 = self.roundtrip(hopper(), icc_profile=icc_profile)
             assert_image_equal(im1, im2)
-            self.assertFalse(im1.info.get("icc_profile"))
-            self.assertTrue(im2.info.get("icc_profile"))
+            assert not im1.info.get("icc_profile")
+            assert im2.info.get("icc_profile")
 
     def test_icc_big(self):
         # Make sure that the "extra" support handles large blocks
@@ -125,9 +124,9 @@ class TestFileJpeg(PillowTestCase):
             # using a 4-byte test code should allow us to detect out of
             # order issues.
             icc_profile = (b"Test" * int(n / 4 + 1))[:n]
-            self.assertEqual(len(icc_profile), n)  # sanity
+            assert len(icc_profile) == n  # sanity
             im1 = self.roundtrip(hopper(), icc_profile=icc_profile)
-            self.assertEqual(im1.info.get("icc_profile"), icc_profile or None)
+            assert im1.info.get("icc_profile") == (icc_profile or None)
 
         test(0)
         test(1)
@@ -163,8 +162,8 @@ class TestFileJpeg(PillowTestCase):
         im3 = self.roundtrip(hopper(), optimize=1)
         assert_image_equal(im1, im2)
         assert_image_equal(im1, im3)
-        self.assertGreaterEqual(im1.bytes, im2.bytes)
-        self.assertGreaterEqual(im1.bytes, im3.bytes)
+        assert im1.bytes >= im2.bytes
+        assert im1.bytes >= im3.bytes
 
     def test_optimize_large_buffer(self):
         # https://github.com/python-pillow/Pillow/issues/148
@@ -177,12 +176,12 @@ class TestFileJpeg(PillowTestCase):
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), progressive=False)
         im3 = self.roundtrip(hopper(), progressive=True)
-        self.assertFalse(im1.info.get("progressive"))
-        self.assertFalse(im2.info.get("progressive"))
-        self.assertTrue(im3.info.get("progressive"))
+        assert not im1.info.get("progressive")
+        assert not im2.info.get("progressive")
+        assert im3.info.get("progressive")
 
         assert_image_equal(im1, im3)
-        self.assertGreaterEqual(im1.bytes, im3.bytes)
+        assert im1.bytes >= im3.bytes
 
     def test_progressive_large_buffer(self):
         f = self.tempfile("temp.jpg")
@@ -229,7 +228,7 @@ class TestFileJpeg(PillowTestCase):
             exif = im._getexif()
 
         # Assert
-        self.assertEqual(exif[gps_index], expected_exif_gps)
+        assert exif[gps_index] == expected_exif_gps
 
     def test_exif_rollback(self):
         # rolling back exif support in 3.1 to pre-3.0 formatting.
@@ -264,7 +263,7 @@ class TestFileJpeg(PillowTestCase):
             exif = im._getexif()
 
         for tag, value in expected_exif.items():
-            self.assertEqual(value, exif[tag])
+            assert value == exif[tag]
 
     def test_exif_gps_typeerror(self):
         with Image.open("Tests/images/exif_gps_typeerror.jpg") as im:
@@ -274,30 +273,30 @@ class TestFileJpeg(PillowTestCase):
 
     def test_progressive_compat(self):
         im1 = self.roundtrip(hopper())
-        self.assertFalse(im1.info.get("progressive"))
-        self.assertFalse(im1.info.get("progression"))
+        assert not im1.info.get("progressive")
+        assert not im1.info.get("progression")
 
         im2 = self.roundtrip(hopper(), progressive=0)
         im3 = self.roundtrip(hopper(), progression=0)  # compatibility
-        self.assertFalse(im2.info.get("progressive"))
-        self.assertFalse(im2.info.get("progression"))
-        self.assertFalse(im3.info.get("progressive"))
-        self.assertFalse(im3.info.get("progression"))
+        assert not im2.info.get("progressive")
+        assert not im2.info.get("progression")
+        assert not im3.info.get("progressive")
+        assert not im3.info.get("progression")
 
         im2 = self.roundtrip(hopper(), progressive=1)
         im3 = self.roundtrip(hopper(), progression=1)  # compatibility
         assert_image_equal(im1, im2)
         assert_image_equal(im1, im3)
-        self.assertTrue(im2.info.get("progressive"))
-        self.assertTrue(im2.info.get("progression"))
-        self.assertTrue(im3.info.get("progressive"))
-        self.assertTrue(im3.info.get("progression"))
+        assert im2.info.get("progressive")
+        assert im2.info.get("progression")
+        assert im3.info.get("progressive")
+        assert im3.info.get("progression")
 
     def test_quality(self):
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), quality=50)
         assert_image(im1, im2.mode, im2.size)
-        self.assertGreaterEqual(im1.bytes, im2.bytes)
+        assert im1.bytes >= im2.bytes
 
     def test_smooth(self):
         im1 = self.roundtrip(hopper())
@@ -311,35 +310,36 @@ class TestFileJpeg(PillowTestCase):
 
         # experimental API
         im = self.roundtrip(hopper(), subsampling=-1)  # default
-        self.assertEqual(getsampling(im), (2, 2, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 2, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling=0)  # 4:4:4
-        self.assertEqual(getsampling(im), (1, 1, 1, 1, 1, 1))
+        assert getsampling(im) == (1, 1, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling=1)  # 4:2:2
-        self.assertEqual(getsampling(im), (2, 1, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 1, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling=2)  # 4:2:0
-        self.assertEqual(getsampling(im), (2, 2, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 2, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling=3)  # default (undefined)
-        self.assertEqual(getsampling(im), (2, 2, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 2, 1, 1, 1, 1)
 
         im = self.roundtrip(hopper(), subsampling="4:4:4")
-        self.assertEqual(getsampling(im), (1, 1, 1, 1, 1, 1))
+        assert getsampling(im) == (1, 1, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling="4:2:2")
-        self.assertEqual(getsampling(im), (2, 1, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 1, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling="4:2:0")
-        self.assertEqual(getsampling(im), (2, 2, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 2, 1, 1, 1, 1)
         im = self.roundtrip(hopper(), subsampling="4:1:1")
-        self.assertEqual(getsampling(im), (2, 2, 1, 1, 1, 1))
+        assert getsampling(im) == (2, 2, 1, 1, 1, 1)
 
-        self.assertRaises(TypeError, self.roundtrip, hopper(), subsampling="1:1:1")
+        with pytest.raises(TypeError):
+            self.roundtrip(hopper(), subsampling="1:1:1")
 
     def test_exif(self):
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             info = im._getexif()
-            self.assertEqual(info[305], "Adobe Photoshop CS Macintosh")
+            assert info[305] == "Adobe Photoshop CS Macintosh"
 
     def test_mp(self):
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
-            self.assertIsNone(im._getmp())
+            assert im._getmp() is None
 
     def test_quality_keep(self):
         # RGB
@@ -372,16 +372,16 @@ class TestFileJpeg(PillowTestCase):
         with Image.open(filename) as im:
             im.load()
             ImageFile.LOAD_TRUNCATED_IMAGES = False
-            self.assertIsNotNone(im.getbbox())
+            assert im.getbbox() is not None
 
     def test_truncated_jpeg_throws_IOError(self):
         filename = "Tests/images/truncated_jpeg.jpg"
         with Image.open(filename) as im:
-            with self.assertRaises(IOError):
+            with pytest.raises(IOError):
                 im.load()
 
             # Test that the error is raised if loaded a second time
-            with self.assertRaises(IOError):
+            with pytest.raises(IOError):
                 im.load()
 
     def _n_qtables_helper(self, n, test_file):
@@ -389,15 +389,15 @@ class TestFileJpeg(PillowTestCase):
             f = self.tempfile("temp.jpg")
             im.save(f, qtables=[[n] * 64] * n)
         with Image.open(f) as im:
-            self.assertEqual(len(im.quantization), n)
+            assert len(im.quantization) == n
             reloaded = self.roundtrip(im, qtables="keep")
-            self.assertEqual(im.quantization, reloaded.quantization)
+            assert im.quantization == reloaded.quantization
 
     def test_qtables(self):
         with Image.open("Tests/images/hopper.jpg") as im:
             qtables = im.quantization
             reloaded = self.roundtrip(im, qtables=qtables, subsampling=0)
-            self.assertEqual(im.quantization, reloaded.quantization)
+            assert im.quantization == reloaded.quantization
             assert_image_similar(im, self.roundtrip(im, qtables="web_low"), 30)
             assert_image_similar(im, self.roundtrip(im, qtables="web_high"), 30)
             assert_image_similar(im, self.roundtrip(im, qtables="keep"), 30)
@@ -475,16 +475,21 @@ class TestFileJpeg(PillowTestCase):
             self._n_qtables_helper(4, "Tests/images/pil_sample_cmyk.jpg")
 
             # not a sequence
-            self.assertRaises(ValueError, self.roundtrip, im, qtables="a")
+            with pytest.raises(ValueError):
+                self.roundtrip(im, qtables="a")
             # sequence wrong length
-            self.assertRaises(ValueError, self.roundtrip, im, qtables=[])
+            with pytest.raises(ValueError):
+                self.roundtrip(im, qtables=[])
             # sequence wrong length
-            self.assertRaises(ValueError, self.roundtrip, im, qtables=[1, 2, 3, 4, 5])
+            with pytest.raises(ValueError):
+                self.roundtrip(im, qtables=[1, 2, 3, 4, 5])
 
             # qtable entry not a sequence
-            self.assertRaises(ValueError, self.roundtrip, im, qtables=[1])
+            with pytest.raises(ValueError):
+                self.roundtrip(im, qtables=[1])
             # qtable entry has wrong number of items
-            self.assertRaises(ValueError, self.roundtrip, im, qtables=[[1, 2, 3, 4]])
+            with pytest.raises(ValueError):
+                self.roundtrip(im, qtables=[[1, 2, 3, 4]])
 
     @unittest.skipUnless(djpeg_available(), "djpeg not available")
     def test_load_djpeg(self):
@@ -505,8 +510,8 @@ class TestFileJpeg(PillowTestCase):
         tag_ids = {v: k for k, v in ExifTags.TAGS.items()}
 
         # Assert
-        self.assertEqual(tag_ids["RelatedImageWidth"], 0x1001)
-        self.assertEqual(tag_ids["RelatedImageLength"], 0x1002)
+        assert tag_ids["RelatedImageWidth"] == 0x1001
+        assert tag_ids["RelatedImageLength"] == 0x1002
 
     def test_MAXBLOCK_scaling(self):
         im = self.gen_random_image((512, 512))
@@ -529,7 +534,7 @@ class TestFileJpeg(PillowTestCase):
         with pytest.warns(UserWarning, Image.open, fn) as im:
 
             # Assert
-            self.assertEqual(im.format, "JPEG")
+            assert im.format == "JPEG"
 
     def test_save_correct_modes(self):
         out = BytesIO()
@@ -542,7 +547,8 @@ class TestFileJpeg(PillowTestCase):
         out = BytesIO()
         for mode in ["LA", "La", "RGBA", "RGBa", "P"]:
             img = Image.new(mode, (20, 20))
-            self.assertRaises(IOError, img.save, out, "JPEG")
+            with pytest.raises(IOError):
+                img.save(out, "JPEG")
 
     def test_save_tiff_with_dpi(self):
         # Arrange
@@ -555,16 +561,16 @@ class TestFileJpeg(PillowTestCase):
             # Assert
             with Image.open(outfile) as reloaded:
                 reloaded.load()
-                self.assertEqual(im.info["dpi"], reloaded.info["dpi"])
+                assert im.info["dpi"] == reloaded.info["dpi"]
 
     def test_load_dpi_rounding(self):
         # Round up
         with Image.open("Tests/images/iptc_roundUp.jpg") as im:
-            self.assertEqual(im.info["dpi"], (44, 44))
+            assert im.info["dpi"] == (44, 44)
 
         # Round down
         with Image.open("Tests/images/iptc_roundDown.jpg") as im:
-            self.assertEqual(im.info["dpi"], (2, 2))
+            assert im.info["dpi"] == (2, 2)
 
     def test_save_dpi_rounding(self):
         outfile = self.tempfile("temp.jpg")
@@ -572,12 +578,12 @@ class TestFileJpeg(PillowTestCase):
             im.save(outfile, dpi=(72.2, 72.2))
 
             with Image.open(outfile) as reloaded:
-                self.assertEqual(reloaded.info["dpi"], (72, 72))
+                assert reloaded.info["dpi"] == (72, 72)
 
             im.save(outfile, dpi=(72.8, 72.8))
 
         with Image.open(outfile) as reloaded:
-            self.assertEqual(reloaded.info["dpi"], (73, 73))
+            assert reloaded.info["dpi"] == (73, 73)
 
     def test_dpi_tuple_from_exif(self):
         # Arrange
@@ -586,7 +592,7 @@ class TestFileJpeg(PillowTestCase):
         with Image.open("Tests/images/photoshop-200dpi.jpg") as im:
 
             # Act / Assert
-            self.assertEqual(im.info.get("dpi"), (200, 200))
+            assert im.info.get("dpi") == (200, 200)
 
     def test_dpi_int_from_exif(self):
         # Arrange
@@ -595,7 +601,7 @@ class TestFileJpeg(PillowTestCase):
         with Image.open("Tests/images/exif-72dpi-int.jpg") as im:
 
             # Act / Assert
-            self.assertEqual(im.info.get("dpi"), (72, 72))
+            assert im.info.get("dpi") == (72, 72)
 
     def test_dpi_from_dpcm_exif(self):
         # Arrange
@@ -604,7 +610,7 @@ class TestFileJpeg(PillowTestCase):
         with Image.open("Tests/images/exif-200dpcm.jpg") as im:
 
             # Act / Assert
-            self.assertEqual(im.info.get("dpi"), (508, 508))
+            assert im.info.get("dpi") == (508, 508)
 
     def test_dpi_exif_zero_division(self):
         # Arrange
@@ -614,7 +620,7 @@ class TestFileJpeg(PillowTestCase):
 
             # Act / Assert
             # This should return the default, and not raise a ZeroDivisionError
-            self.assertEqual(im.info.get("dpi"), (72, 72))
+            assert im.info.get("dpi") == (72, 72)
 
     def test_no_dpi_in_exif(self):
         # Arrange
@@ -625,7 +631,7 @@ class TestFileJpeg(PillowTestCase):
             # Act / Assert
             # "When the image resolution is unknown, 72 [dpi] is designated."
             # http://www.exiv2.org/tags.html
-            self.assertEqual(im.info.get("dpi"), (72, 72))
+            assert im.info.get("dpi") == (72, 72)
 
     def test_invalid_exif(self):
         # This is no-dpi-in-exif with the tiff header of the exif block
@@ -634,7 +640,7 @@ class TestFileJpeg(PillowTestCase):
 
             # This should return the default, and not a SyntaxError or
             # OSError for unidentified image.
-            self.assertEqual(im.info.get("dpi"), (72, 72))
+            assert im.info.get("dpi") == (72, 72)
 
     def test_invalid_exif_x_resolution(self):
         # When no x or y resolution is defined in EXIF
@@ -642,7 +648,7 @@ class TestFileJpeg(PillowTestCase):
 
             # This should return the default, and not a ValueError or
             # OSError for an unidentified image.
-            self.assertEqual(im.info.get("dpi"), (72, 72))
+            assert im.info.get("dpi") == (72, 72)
 
     def test_ifd_offset_exif(self):
         # Arrange
@@ -651,19 +657,16 @@ class TestFileJpeg(PillowTestCase):
         with Image.open("Tests/images/exif-ifd-offset.jpg") as im:
 
             # Act / Assert
-            self.assertEqual(im._getexif()[306], "2017:03:13 23:03:09")
+            assert im._getexif()[306] == "2017:03:13 23:03:09"
 
     def test_photoshop(self):
         with Image.open("Tests/images/photoshop-200dpi.jpg") as im:
-            self.assertEqual(
-                im.info["photoshop"][0x03ED],
-                {
-                    "XResolution": 200.0,
-                    "DisplayedUnitsX": 1,
-                    "YResolution": 200.0,
-                    "DisplayedUnitsY": 1,
-                },
-            )
+            assert im.info["photoshop"][0x03ED] == {
+                "XResolution": 200.0,
+                "DisplayedUnitsX": 1,
+                "YResolution": 200.0,
+                "DisplayedUnitsY": 1,
+            }
 
             # Test that the image can still load, even with broken Photoshop data
             # This image had the APP13 length hexedited to be smaller
@@ -672,14 +675,14 @@ class TestFileJpeg(PillowTestCase):
 
         # This image does not contain a Photoshop header string
         with Image.open("Tests/images/app13.jpg") as im:
-            self.assertNotIn("photoshop", im.info)
+            assert "photoshop" not in im.info
 
     def test_photoshop_malformed_and_multiple(self):
         with Image.open("Tests/images/app13-multiple.jpg") as im:
-            self.assertIn("photoshop", im.info)
-            self.assertEqual(24, len(im.info["photoshop"]))
+            assert "photoshop" in im.info
+            assert 24 == len(im.info["photoshop"])
             apps_13_lengths = [len(v) for k, v in im.applist if k == "APP13"]
-            self.assertEqual([65504, 24], apps_13_lengths)
+            assert [65504, 24] == apps_13_lengths
 
 
 @unittest.skipUnless(is_win32(), "Windows only")
@@ -693,9 +696,10 @@ class TestFileCloseW32(PillowTestCase):
 
         im = Image.open(tmpfile)
         fp = im.fp
-        self.assertFalse(fp.closed)
-        self.assertRaises(WindowsError, os.remove, tmpfile)
+        assert not fp.closed
+        with pytest.raises(WindowsError):
+            os.remove(tmpfile)
         im.load()
-        self.assertTrue(fp.closed)
+        assert fp.closed
         # this should not fail, as load should have closed the file.
         os.remove(tmpfile)

Tests/test_file_jpeg2k.py

@@ -38,21 +38,22 @@ class TestFileJpeg2k(PillowTestCase):
 
         with Image.open("Tests/images/test-card-lossless.jp2") as im:
             px = im.load()
-            self.assertEqual(px[0, 0], (0, 0, 0))
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (640, 480))
-            self.assertEqual(im.format, "JPEG2000")
-            self.assertEqual(im.get_format_mimetype(), "image/jp2")
+            assert px[0, 0] == (0, 0, 0)
+            assert im.mode == "RGB"
+            assert im.size == (640, 480)
+            assert im.format == "JPEG2000"
+            assert im.get_format_mimetype() == "image/jp2"
 
     def test_jpf(self):
         with Image.open("Tests/images/balloon.jpf") as im:
-            self.assertEqual(im.format, "JPEG2000")
-            self.assertEqual(im.get_format_mimetype(), "image/jpx")
+            assert im.format == "JPEG2000"
+            assert im.get_format_mimetype() == "image/jpx"
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, Jpeg2KImagePlugin.Jpeg2KImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            Jpeg2KImagePlugin.Jpeg2KImageFile(invalid_file)
 
     def test_bytesio(self):
         with open("Tests/images/test-card-lossless.jp2", "rb") as f:
@@ -95,7 +96,7 @@ class TestFileJpeg2k(PillowTestCase):
         assert_image_equal(im, test_card)
 
     def test_tiled_offset_too_small(self):
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             self.roundtrip(
                 test_card, tile_size=(128, 128), tile_offset=(0, 0), offset=(128, 32)
             )
@@ -116,7 +117,7 @@ class TestFileJpeg2k(PillowTestCase):
         with Image.open("Tests/images/test-card-lossless.jp2") as im:
             im.reduce = 2
             im.load()
-            self.assertEqual(im.size, (160, 120))
+            assert im.size == (160, 120)
 
     def test_layers_type(self):
         outfile = self.tempfile("temp_layers.jp2")
@@ -124,9 +125,8 @@ class TestFileJpeg2k(PillowTestCase):
             test_card.save(outfile, quality_layers=quality_layers)
 
         for quality_layers in ["quality_layers", ("100", "50", "10")]:
-            self.assertRaises(
-                ValueError, test_card.save, outfile, quality_layers=quality_layers
-            )
+            with pytest.raises(ValueError):
+                test_card.save(outfile, quality_layers=quality_layers)
 
     def test_layers(self):
         out = BytesIO()
@@ -156,17 +156,17 @@ class TestFileJpeg2k(PillowTestCase):
                 jp2.load()
 
                 # Assert
-                self.assertEqual(j2k.mode, "RGBA")
-                self.assertEqual(jp2.mode, "RGBA")
+                assert j2k.mode == "RGBA"
+                assert jp2.mode == "RGBA"
 
     def test_16bit_monochrome_has_correct_mode(self):
         with Image.open("Tests/images/16bit.cropped.j2k") as j2k:
             j2k.load()
-            self.assertEqual(j2k.mode, "I;16")
+            assert j2k.mode == "I;16"
 
         with Image.open("Tests/images/16bit.cropped.jp2") as jp2:
             jp2.load()
-            self.assertEqual(jp2.mode, "I;16")
+            assert jp2.mode == "I;16"
 
     @pytest.mark.xfail(is_big_endian() and on_ci(), reason="Fails on big-endian")
     def test_16bit_monochrome_jp2_like_tiff(self):
@@ -193,7 +193,7 @@ class TestFileJpeg2k(PillowTestCase):
     def test_unbound_local(self):
         # prepatch, a malformed jp2 file could cause an UnboundLocalError
         # exception.
-        with self.assertRaises(IOError):
+        with pytest.raises(IOError):
             Image.open("Tests/images/unbound_variable.jp2")
 
     def test_parser_feed(self):
@@ -206,4 +206,4 @@ class TestFileJpeg2k(PillowTestCase):
         p.feed(data)
 
         # Assert
-        self.assertEqual(p.image.size, (640, 480))
+        assert p.image.size == (640, 480)

Tests/test_file_libtiff.py

@@ -6,6 +6,7 @@ import os
 from collections import namedtuple
 from ctypes import c_float
 
+import pytest
 from PIL import Image, ImageFilter, TiffImagePlugin, TiffTags
 
 from .helper import (
@@ -26,14 +27,14 @@ class LibTiffTestCase(PillowTestCase):
     def _assert_noerr(self, im):
         """Helper tests that assert basic sanity about the g4 tiff reading"""
         # 1 bit
-        self.assertEqual(im.mode, "1")
+        assert im.mode == "1"
 
         # Does the data actually load
         im.load()
         im.getdata()
 
         try:
-            self.assertEqual(im._compression, "group4")
+            assert im._compression == "group4"
         except AttributeError:
             print("No _compression")
             print(dir(im))
@@ -52,7 +53,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
         test_file = "Tests/images/hopper_g4_500.tif"
         with Image.open(test_file) as im:
-            self.assertEqual(im.size, (500, 500))
+            assert im.size == (500, 500)
             self._assert_noerr(im)
 
     def test_g4_large(self):
@@ -66,7 +67,7 @@ class TestFileLibTiff(LibTiffTestCase):
         test_file = "Tests/images/hopper_g4_500.tif"
         with open(test_file, "rb") as f:
             with Image.open(f) as im:
-                self.assertEqual(im.size, (500, 500))
+                assert im.size == (500, 500)
                 self._assert_noerr(im)
 
     def test_g4_tiff_bytesio(self):
@@ -77,7 +78,7 @@ class TestFileLibTiff(LibTiffTestCase):
             s.write(f.read())
             s.seek(0)
         with Image.open(s) as im:
-            self.assertEqual(im.size, (500, 500))
+            assert im.size == (500, 500)
             self._assert_noerr(im)
 
     def test_g4_non_disk_file_object(self):
@@ -89,7 +90,7 @@ class TestFileLibTiff(LibTiffTestCase):
             s.seek(0)
         r = io.BufferedReader(s)
         with Image.open(r) as im:
-            self.assertEqual(im.size, (500, 500))
+            assert im.size == (500, 500)
             self._assert_noerr(im)
 
     def test_g4_eq_png(self):
@@ -111,25 +112,25 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(test_file) as orig:
             out = self.tempfile("temp.tif")
             rot = orig.transpose(Image.ROTATE_90)
-            self.assertEqual(rot.size, (500, 500))
+            assert rot.size == (500, 500)
             rot.save(out)
 
             with Image.open(out) as reread:
-                self.assertEqual(reread.size, (500, 500))
+                assert reread.size == (500, 500)
                 self._assert_noerr(reread)
                 assert_image_equal(reread, rot)
-                self.assertEqual(reread.info["compression"], "group4")
+                assert reread.info["compression"] == "group4"
 
-                self.assertEqual(reread.info["compression"], orig.info["compression"])
+                assert reread.info["compression"] == orig.info["compression"]
 
-                self.assertNotEqual(orig.tobytes(), reread.tobytes())
+                assert orig.tobytes() != reread.tobytes()
 
     def test_adobe_deflate_tiff(self):
         test_file = "Tests/images/tiff_adobe_deflate.tif"
         with Image.open(test_file) as im:
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (278, 374))
-            self.assertEqual(im.tile[0][:3], ("libtiff", (0, 0, 278, 374), 0))
+            assert im.mode == "RGB"
+            assert im.size == (278, 374)
+            assert im.tile[0][:3] == ("libtiff", (0, 0, 278, 374), 0)
             im.load()
 
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
@@ -166,24 +167,21 @@ class TestFileLibTiff(LibTiffTestCase):
                     val = original[tag]
                     if tag.endswith("Resolution"):
                         if legacy_api:
-                            self.assertEqual(
-                                c_float(val[0][0] / val[0][1]).value,
-                                c_float(value[0][0] / value[0][1]).value,
-                                msg="%s didn't roundtrip" % tag,
-                            )
+                            assert (
+                                c_float(val[0][0] / val[0][1]).value
+                                == c_float(value[0][0] / value[0][1]).value
+                            ), ("%s didn't roundtrip" % tag)
                         else:
-                            self.assertEqual(
-                                c_float(val).value,
-                                c_float(value).value,
-                                msg="%s didn't roundtrip" % tag,
+                            assert c_float(val).value == c_float(value).value, (
+                                "%s didn't roundtrip" % tag
                             )
                     else:
-                        self.assertEqual(val, value, msg="%s didn't roundtrip" % tag)
+                        assert val == value, "%s didn't roundtrip" % tag
 
             # https://github.com/python-pillow/Pillow/issues/1561
             requested_fields = ["StripByteCounts", "RowsPerStrip", "StripOffsets"]
             for field in requested_fields:
-                self.assertIn(field, reloaded, "%s not in metadata" % field)
+                assert field in reloaded, "%s not in metadata" % field
 
     def test_additional_metadata(self):
         # these should not crash. Seriously dummy data, most of it doesn't make
@@ -303,7 +301,7 @@ class TestFileLibTiff(LibTiffTestCase):
                         if libtiff and isinstance(value, bytes):
                             value = value.decode()
 
-                        self.assertEqual(reloaded_value, value)
+                        assert reloaded_value == value
 
             # Test with types
             ifd = TiffImagePlugin.ImageFileDirectory_v2()
@@ -331,7 +329,7 @@ class TestFileLibTiff(LibTiffTestCase):
         im.save(out, dpi=(72, 72))
         TiffImagePlugin.WRITE_LIBTIFF = False
         with Image.open(out) as reloaded:
-            self.assertEqual(reloaded.info["dpi"], (72.0, 72.0))
+            assert reloaded.info["dpi"] == (72.0, 72.0)
 
     def test_g3_compression(self):
         with Image.open("Tests/images/hopper_g4_500.tif") as i:
@@ -339,44 +337,44 @@ class TestFileLibTiff(LibTiffTestCase):
             i.save(out, compression="group3")
 
             with Image.open(out) as reread:
-                self.assertEqual(reread.info["compression"], "group3")
+                assert reread.info["compression"] == "group3"
                 assert_image_equal(reread, i)
 
     def test_little_endian(self):
         with Image.open("Tests/images/16bit.deflate.tif") as im:
-            self.assertEqual(im.getpixel((0, 0)), 480)
-            self.assertEqual(im.mode, "I;16")
+            assert im.getpixel((0, 0)) == 480
+            assert im.mode == "I;16"
 
             b = im.tobytes()
             # Bytes are in image native order (little endian)
-            self.assertEqual(b[0], ord(b"\xe0"))
-            self.assertEqual(b[1], ord(b"\x01"))
+            assert b[0] == ord(b"\xe0")
+            assert b[1] == ord(b"\x01")
 
             out = self.tempfile("temp.tif")
             # out = "temp.le.tif"
             im.save(out)
         with Image.open(out) as reread:
-            self.assertEqual(reread.info["compression"], im.info["compression"])
-            self.assertEqual(reread.getpixel((0, 0)), 480)
+            assert reread.info["compression"] == im.info["compression"]
+            assert reread.getpixel((0, 0)) == 480
         # UNDONE - libtiff defaults to writing in native endian, so
         # on big endian, we'll get back mode = 'I;16B' here.
 
     def test_big_endian(self):
         with Image.open("Tests/images/16bit.MM.deflate.tif") as im:
-            self.assertEqual(im.getpixel((0, 0)), 480)
-            self.assertEqual(im.mode, "I;16B")
+            assert im.getpixel((0, 0)) == 480
+            assert im.mode == "I;16B"
 
             b = im.tobytes()
 
             # Bytes are in image native order (big endian)
-            self.assertEqual(b[0], ord(b"\x01"))
-            self.assertEqual(b[1], ord(b"\xe0"))
+            assert b[0] == ord(b"\x01")
+            assert b[1] == ord(b"\xe0")
 
             out = self.tempfile("temp.tif")
             im.save(out)
             with Image.open(out) as reread:
-                self.assertEqual(reread.info["compression"], im.info["compression"])
-                self.assertEqual(reread.getpixel((0, 0)), 480)
+                assert reread.info["compression"] == im.info["compression"]
+                assert reread.getpixel((0, 0)) == 480
 
     def test_g4_string_info(self):
         """Tests String data in info directory"""
@@ -388,8 +386,8 @@ class TestFileLibTiff(LibTiffTestCase):
             orig.save(out)
 
         with Image.open(out) as reread:
-            self.assertEqual("temp.tif", reread.tag_v2[269])
-            self.assertEqual("temp.tif", reread.tag[269][0])
+            assert "temp.tif" == reread.tag_v2[269]
+            assert "temp.tif" == reread.tag[269][0]
 
     def test_12bit_rawmode(self):
         """ Are we generating the same interpretation
@@ -445,18 +443,22 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(out) as im3:
             assert_image_similar(im2, im3, 30)
 
-        self.assertGreater(size_raw, size_compressed)
-        self.assertGreater(size_compressed, size_jpeg)
-        self.assertGreater(size_jpeg, size_jpeg_30)
+        assert size_raw > size_compressed
+        assert size_compressed > size_jpeg
+        assert size_jpeg > size_jpeg_30
 
     def test_quality(self):
         im = hopper("RGB")
         out = self.tempfile("temp.tif")
 
-        self.assertRaises(ValueError, im.save, out, compression="tiff_lzw", quality=50)
-        self.assertRaises(ValueError, im.save, out, compression="jpeg", quality=-1)
-        self.assertRaises(ValueError, im.save, out, compression="jpeg", quality=101)
-        self.assertRaises(ValueError, im.save, out, compression="jpeg", quality="good")
+        with pytest.raises(ValueError):
+            im.save(out, compression="tiff_lzw", quality=50)
+        with pytest.raises(ValueError):
+            im.save(out, compression="jpeg", quality=-1)
+        with pytest.raises(ValueError):
+            im.save(out, compression="jpeg", quality=101)
+        with pytest.raises(ValueError):
+            im.save(out, compression="jpeg", quality="good")
         im.save(out, compression="jpeg", quality=0)
         im.save(out, compression="jpeg", quality=100)
 
@@ -476,9 +478,12 @@ class TestFileLibTiff(LibTiffTestCase):
         im = hopper("RGB")
         out = self.tempfile("temp.tif")
 
-        self.assertRaises(IOError, im.save, out, compression="tiff_ccitt")
-        self.assertRaises(IOError, im.save, out, compression="group3")
-        self.assertRaises(IOError, im.save, out, compression="group4")
+        with pytest.raises(IOError):
+            im.save(out, compression="tiff_ccitt")
+        with pytest.raises(IOError):
+            im.save(out, compression="group3")
+        with pytest.raises(IOError):
+            im.save(out, compression="group4")
 
     def test_fp_leak(self):
         im = Image.open("Tests/images/hopper_g4_500.tif")
@@ -486,10 +491,13 @@ class TestFileLibTiff(LibTiffTestCase):
 
         os.fstat(fn)
         im.load()  # this should close it.
-        self.assertRaises(OSError, os.fstat, fn)
+        with pytest.raises(OSError):
+            os.fstat(fn)
         im = None  # this should force even more closed.
-        self.assertRaises(OSError, os.fstat, fn)
-        self.assertRaises(OSError, os.close, fn)
+        with pytest.raises(OSError):
+            os.fstat(fn)
+        with pytest.raises(OSError):
+            os.close(fn)
 
     def test_multipage(self):
         # issue #862
@@ -498,19 +506,19 @@ class TestFileLibTiff(LibTiffTestCase):
             # file is a multipage tiff,  10x10 green, 10x10 red, 20x20 blue
 
             im.seek(0)
-            self.assertEqual(im.size, (10, 10))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 128, 0))
-            self.assertTrue(im.tag.next)
+            assert im.size == (10, 10)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 128, 0)
+            assert im.tag.next
 
             im.seek(1)
-            self.assertEqual(im.size, (10, 10))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (255, 0, 0))
-            self.assertTrue(im.tag.next)
+            assert im.size == (10, 10)
+            assert im.convert("RGB").getpixel((0, 0)) == (255, 0, 0)
+            assert im.tag.next
 
             im.seek(2)
-            self.assertFalse(im.tag.next)
-            self.assertEqual(im.size, (20, 20))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 0, 255))
+            assert not im.tag.next
+            assert im.size == (20, 20)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 255)
 
         TiffImagePlugin.READ_LIBTIFF = False
 
@@ -519,7 +527,7 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/multipage.tiff") as im:
             frames = im.n_frames
-            self.assertEqual(frames, 3)
+            assert frames == 3
             for _ in range(frames):
                 im.seek(0)
                 # Should not raise ValueError: I/O operation on closed file
@@ -530,9 +538,9 @@ class TestFileLibTiff(LibTiffTestCase):
     def test__next(self):
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/hopper.tif") as im:
-            self.assertFalse(im.tag.next)
+            assert not im.tag.next
             im.load()
-            self.assertFalse(im.tag.next)
+            assert not im.tag.next
 
     def test_4bit(self):
         # Arrange
@@ -545,8 +553,8 @@ class TestFileLibTiff(LibTiffTestCase):
             TiffImagePlugin.READ_LIBTIFF = False
 
             # Assert
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.mode, "L")
+            assert im.size == (128, 128)
+            assert im.mode == "L"
             assert_image_similar(im, original, 7.3)
 
     def test_gray_semibyte_per_pixel(self):
@@ -573,13 +581,13 @@ class TestFileLibTiff(LibTiffTestCase):
         original = hopper("L")
         for epsilon, group in test_files:
             with Image.open(group[0]) as im:
-                self.assertEqual(im.size, (128, 128))
-                self.assertEqual(im.mode, "L")
+                assert im.size == (128, 128)
+                assert im.mode == "L"
                 assert_image_similar(im, original, epsilon)
             for file in group[1:]:
                 with Image.open(file) as im2:
-                    self.assertEqual(im2.size, (128, 128))
-                    self.assertEqual(im2.mode, "L")
+                    assert im2.size == (128, 128)
+                    assert im2.mode == "L"
                     assert_image_equal(im, im2)
 
     def test_save_bytesio(self):
@@ -650,29 +658,29 @@ class TestFileLibTiff(LibTiffTestCase):
     def test_read_icc(self):
         with Image.open("Tests/images/hopper.iccprofile.tif") as img:
             icc = img.info.get("icc_profile")
-            self.assertIsNotNone(icc)
+            assert icc is not None
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/hopper.iccprofile.tif") as img:
             icc_libtiff = img.info.get("icc_profile")
-            self.assertIsNotNone(icc_libtiff)
+            assert icc_libtiff is not None
         TiffImagePlugin.READ_LIBTIFF = False
-        self.assertEqual(icc, icc_libtiff)
+        assert icc == icc_libtiff
 
     def test_multipage_compression(self):
         with Image.open("Tests/images/compression.tif") as im:
 
             im.seek(0)
-            self.assertEqual(im._compression, "tiff_ccitt")
-            self.assertEqual(im.size, (10, 10))
+            assert im._compression == "tiff_ccitt"
+            assert im.size == (10, 10)
 
             im.seek(1)
-            self.assertEqual(im._compression, "packbits")
-            self.assertEqual(im.size, (10, 10))
+            assert im._compression == "packbits"
+            assert im.size == (10, 10)
             im.load()
 
             im.seek(0)
-            self.assertEqual(im._compression, "tiff_ccitt")
-            self.assertEqual(im.size, (10, 10))
+            assert im._compression == "tiff_ccitt"
+            assert im.size == (10, 10)
             im.load()
 
     def test_save_tiff_with_jpegtables(self):
@@ -689,38 +697,27 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_16bit_RGB_tiff(self):
         with Image.open("Tests/images/tiff_16bit_RGB.tiff") as im:
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (100, 40))
-            self.assertEqual(
-                im.tile,
-                [
-                    (
-                        "libtiff",
-                        (0, 0, 100, 40),
-                        0,
-                        ("RGB;16N", "tiff_adobe_deflate", False, 8),
-                    )
-                ],
-            )
+            assert im.mode == "RGB"
+            assert im.size == (100, 40)
+            assert im.tile, [
+                (
+                    "libtiff",
+                    (0, 0, 100, 40),
+                    0,
+                    ("RGB;16N", "tiff_adobe_deflate", False, 8),
+                )
+            ]
             im.load()
 
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGB_target.png")
 
     def test_16bit_RGBa_tiff(self):
         with Image.open("Tests/images/tiff_16bit_RGBa.tiff") as im:
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (100, 40))
-            self.assertEqual(
-                im.tile,
-                [
-                    (
-                        "libtiff",
-                        (0, 0, 100, 40),
-                        0,
-                        ("RGBa;16N", "tiff_lzw", False, 38236),
-                    )
-                ],
-            )
+            assert im.mode == "RGBA"
+            assert im.size == (100, 40)
+            assert im.tile, [
+                ("libtiff", (0, 0, 100, 40), 0, ("RGBa;16N", "tiff_lzw", False, 38236),)
+            ]
             im.load()
 
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
@@ -730,12 +727,11 @@ class TestFileLibTiff(LibTiffTestCase):
         # Read TIFF JPEG images from GIMP [@PIL168]
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (256, 256))
-            self.assertEqual(
-                im.tile,
-                [("libtiff", (0, 0, 256, 256), 0, ("RGB", "jpeg", False, 5122))],
-            )
+            assert im.mode == "RGB"
+            assert im.size == (256, 256)
+            assert im.tile == [
+                ("libtiff", (0, 0, 256, 256), 0, ("RGB", "jpeg", False, 5122))
+            ]
             im.load()
 
             assert_image_equal_tofile(im, "Tests/images/pil168.png")
@@ -743,15 +739,15 @@ class TestFileLibTiff(LibTiffTestCase):
     def test_sampleformat(self):
         # https://github.com/python-pillow/Pillow/issues/1466
         with Image.open("Tests/images/copyleft.tiff") as im:
-            self.assertEqual(im.mode, "RGB")
+            assert im.mode == "RGB"
 
             assert_image_equal_tofile(im, "Tests/images/copyleft.png", mode="RGB")
 
     def test_lzw(self):
         with Image.open("Tests/images/hopper_lzw.tif") as im:
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "TIFF")
+            assert im.mode == "RGB"
+            assert im.size == (128, 128)
+            assert im.format == "TIFF"
             im2 = hopper()
             assert_image_similar(im, im2, 5)
 
@@ -800,7 +796,7 @@ class TestFileLibTiff(LibTiffTestCase):
         infile = "Tests/images/no_rows_per_strip.tif"
         with Image.open(infile) as im:
             im.load()
-        self.assertEqual(im.size, (950, 975))
+        assert im.size == (950, 975)
 
     def test_orientation(self):
         with Image.open("Tests/images/g4_orientation_1.tif") as base_im:
@@ -834,9 +830,9 @@ class TestFileLibTiff(LibTiffTestCase):
     def test_realloc_overflow(self):
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/tiff_overflow_rows_per_strip.tif") as im:
-            with self.assertRaises(IOError) as e:
+            with pytest.raises(IOError) as e:
                 im.load()
 
             # Assert that the error code is IMAGING_CODEC_MEMORY
-            self.assertEqual(str(e.exception), "-9")
+            assert str(e.value) == "-9"
         TiffImagePlugin.READ_LIBTIFF = False

Tests/test_file_libtiff_small.py

@@ -21,7 +21,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
         test_file = "Tests/images/hopper_g4.tif"
         with open(test_file, "rb") as f:
             with Image.open(f) as im:
-                self.assertEqual(im.size, (128, 128))
+                assert im.size == (128, 128)
                 self._assert_noerr(im)
 
     def test_g4_hopper_bytesio(self):
@@ -32,7 +32,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
             s.write(f.read())
             s.seek(0)
         with Image.open(s) as im:
-            self.assertEqual(im.size, (128, 128))
+            assert im.size == (128, 128)
             self._assert_noerr(im)
 
     def test_g4_hopper(self):
@@ -40,5 +40,5 @@ class TestFileLibTiffSmall(LibTiffTestCase):
 
         test_file = "Tests/images/hopper_g4.tif"
         with Image.open(test_file) as im:
-            self.assertEqual(im.size, (128, 128))
+            assert im.size == (128, 128)
             self._assert_noerr(im)

Tests/test_file_msp.py

@@ -1,6 +1,7 @@
 import os
 import unittest
 
+import pytest
 from PIL import Image, MspImagePlugin
 
 from .helper import PillowTestCase, assert_image_equal, hopper
@@ -18,14 +19,15 @@ class TestFileMsp(PillowTestCase):
 
         with Image.open(test_file) as im:
             im.load()
-            self.assertEqual(im.mode, "1")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "MSP")
+            assert im.mode == "1"
+            assert im.size == (128, 128)
+            assert im.format == "MSP"
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, MspImagePlugin.MspImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            MspImagePlugin.MspImageFile(invalid_file)
 
     def test_bad_checksum(self):
         # Arrange
@@ -33,7 +35,8 @@ class TestFileMsp(PillowTestCase):
         bad_checksum = "Tests/images/hopper_bad_checksum.msp"
 
         # Act / Assert
-        self.assertRaises(SyntaxError, MspImagePlugin.MspImageFile, bad_checksum)
+        with pytest.raises(SyntaxError):
+            MspImagePlugin.MspImageFile(bad_checksum)
 
     def test_open_windows_v1(self):
         # Arrange
@@ -42,7 +45,7 @@ class TestFileMsp(PillowTestCase):
 
             # Assert
             assert_image_equal(im, hopper("1"))
-            self.assertIsInstance(im, MspImagePlugin.MspImageFile)
+            assert isinstance(im, MspImagePlugin.MspImageFile)
 
     def _assert_file_image_equal(self, source_path, target_path):
         with Image.open(source_path) as im:
@@ -76,4 +79,5 @@ class TestFileMsp(PillowTestCase):
         filename = self.tempfile("temp.msp")
 
         # Act/Assert
-        self.assertRaises(IOError, im.save, filename)
+        with pytest.raises(IOError):
+            im.save(filename)

Tests/test_file_palm.py

@@ -1,5 +1,7 @@
 import os.path
 
+import pytest
+
 from .helper import (
     PillowTestCase,
     assert_image_equal,
@@ -21,8 +23,8 @@ class TestFilePalm(PillowTestCase):
         im.save(outfile)
 
         # Assert
-        self.assertTrue(os.path.isfile(outfile))
-        self.assertGreater(os.path.getsize(outfile), 0)
+        assert os.path.isfile(outfile)
+        assert os.path.getsize(outfile) > 0
 
     def roundtrip(self, mode):
         if not self._roundtrip:
@@ -57,11 +59,13 @@ class TestFilePalm(PillowTestCase):
         mode = "L"
 
         # Act / Assert
-        self.assertRaises(IOError, self.helper_save_as_palm, mode)
+        with pytest.raises(IOError):
+            self.helper_save_as_palm(mode)
 
     def test_rgb_ioerror(self):
         # Arrange
         mode = "RGB"
 
         # Act / Assert
-        self.assertRaises(IOError, self.helper_save_as_palm, mode)
+        with pytest.raises(IOError):
+            self.helper_save_as_palm(mode)

Tests/test_file_pcx.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, ImageFile, PcxImagePlugin
 
 from .helper import PillowTestCase, assert_image_equal, hopper
@@ -8,10 +9,10 @@ class TestFilePcx(PillowTestCase):
         f = self.tempfile("temp.pcx")
         im.save(f)
         with Image.open(f) as im2:
-            self.assertEqual(im2.mode, im.mode)
-            self.assertEqual(im2.size, im.size)
-            self.assertEqual(im2.format, "PCX")
-            self.assertEqual(im2.get_format_mimetype(), "image/x-pcx")
+            assert im2.mode == im.mode
+            assert im2.size == im.size
+            assert im2.format == "PCX"
+            assert im2.get_format_mimetype() == "image/x-pcx"
             assert_image_equal(im2, im)
 
     def test_sanity(self):
@@ -21,12 +22,14 @@ class TestFilePcx(PillowTestCase):
         # Test an unsupported mode
         f = self.tempfile("temp.pcx")
         im = hopper("RGBA")
-        self.assertRaises(ValueError, im.save, f)
+        with pytest.raises(ValueError):
+            im.save(f)
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, PcxImagePlugin.PcxImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            PcxImagePlugin.PcxImageFile(invalid_file)
 
     def test_odd(self):
         # see issue #523, odd sized images should have a stride that's even.
@@ -42,11 +45,11 @@ class TestFilePcx(PillowTestCase):
 
         test_file = "Tests/images/pil184.pcx"
         with Image.open(test_file) as im:
-            self.assertEqual(im.size, (447, 144))
-            self.assertEqual(im.tile[0][1], (0, 0, 447, 144))
+            assert im.size == (447, 144)
+            assert im.tile[0][1] == (0, 0, 447, 144)
 
             # Make sure all pixels are either 0 or 255.
-            self.assertEqual(im.histogram()[0] + im.histogram()[255], 447 * 144)
+            assert im.histogram()[0] + im.histogram()[255] == 447 * 144
 
     def test_1px_width(self):
         im = Image.new("L", (1, 256))

Tests/test_file_pdf.py

@@ -4,6 +4,7 @@ import os.path
 import tempfile
 import time
 
+import pytest
 from PIL import Image, PdfParser
 
 from .helper import PillowTestCase, hopper
@@ -19,20 +20,20 @@ class TestFilePdf(PillowTestCase):
         im.save(outfile, **kwargs)
 
         # Assert
-        self.assertTrue(os.path.isfile(outfile))
-        self.assertGreater(os.path.getsize(outfile), 0)
+        assert os.path.isfile(outfile)
+        assert os.path.getsize(outfile) > 0
         with PdfParser.PdfParser(outfile) as pdf:
             if kwargs.get("append_images", False) or kwargs.get("append", False):
-                self.assertGreater(len(pdf.pages), 1)
+                assert len(pdf.pages) > 1
             else:
-                self.assertGreater(len(pdf.pages), 0)
+                assert len(pdf.pages) > 0
         with open(outfile, "rb") as fp:
             contents = fp.read()
         size = tuple(
             int(d)
             for d in contents.split(b"/MediaBox [ 0 0 ")[1].split(b"]")[0].split()
         )
-        self.assertEqual(im.size, size)
+        assert im.size == size
 
         return outfile
 
@@ -75,7 +76,8 @@ class TestFilePdf(PillowTestCase):
         im = hopper("LA")
         outfile = self.tempfile("temp_LA.pdf")
 
-        self.assertRaises(ValueError, im.save, outfile)
+        with pytest.raises(ValueError):
+            im.save(outfile)
 
     def test_save_all(self):
         # Single frame image
@@ -87,15 +89,15 @@ class TestFilePdf(PillowTestCase):
             outfile = self.tempfile("temp.pdf")
             im.save(outfile, save_all=True)
 
-            self.assertTrue(os.path.isfile(outfile))
-            self.assertGreater(os.path.getsize(outfile), 0)
+            assert os.path.isfile(outfile)
+            assert os.path.getsize(outfile) > 0
 
             # Append images
             ims = [hopper()]
             im.copy().save(outfile, save_all=True, append_images=ims)
 
-            self.assertTrue(os.path.isfile(outfile))
-            self.assertGreater(os.path.getsize(outfile), 0)
+            assert os.path.isfile(outfile)
+            assert os.path.getsize(outfile) > 0
 
             # Test appending using a generator
             def imGenerator(ims):
@@ -103,15 +105,15 @@ class TestFilePdf(PillowTestCase):
 
             im.save(outfile, save_all=True, append_images=imGenerator(ims))
 
-        self.assertTrue(os.path.isfile(outfile))
-        self.assertGreater(os.path.getsize(outfile), 0)
+        assert os.path.isfile(outfile)
+        assert os.path.getsize(outfile) > 0
 
         # Append JPEG images
         with Image.open("Tests/images/flower.jpg") as jpeg:
             jpeg.save(outfile, save_all=True, append_images=[jpeg.copy()])
 
-        self.assertTrue(os.path.isfile(outfile))
-        self.assertGreater(os.path.getsize(outfile), 0)
+        assert os.path.isfile(outfile)
+        assert os.path.getsize(outfile) > 0
 
     def test_multiframe_normal_save(self):
         # Test saving a multiframe image without save_all
@@ -120,69 +122,67 @@ class TestFilePdf(PillowTestCase):
             outfile = self.tempfile("temp.pdf")
             im.save(outfile)
 
-        self.assertTrue(os.path.isfile(outfile))
-        self.assertGreater(os.path.getsize(outfile), 0)
+        assert os.path.isfile(outfile)
+        assert os.path.getsize(outfile) > 0
 
     def test_pdf_open(self):
         # fail on a buffer full of null bytes
-        self.assertRaises(
-            PdfParser.PdfFormatError, PdfParser.PdfParser, buf=bytearray(65536)
-        )
+        with pytest.raises(PdfParser.PdfFormatError):
+            PdfParser.PdfParser(buf=bytearray(65536))
 
         # make an empty PDF object
         with PdfParser.PdfParser() as empty_pdf:
-            self.assertEqual(len(empty_pdf.pages), 0)
-            self.assertEqual(len(empty_pdf.info), 0)
-            self.assertFalse(empty_pdf.should_close_buf)
-            self.assertFalse(empty_pdf.should_close_file)
+            assert len(empty_pdf.pages) == 0
+            assert len(empty_pdf.info) == 0
+            assert not empty_pdf.should_close_buf
+            assert not empty_pdf.should_close_file
 
         # make a PDF file
         pdf_filename = self.helper_save_as_pdf("RGB")
 
         # open the PDF file
         with PdfParser.PdfParser(filename=pdf_filename) as hopper_pdf:
-            self.assertEqual(len(hopper_pdf.pages), 1)
-            self.assertTrue(hopper_pdf.should_close_buf)
-            self.assertTrue(hopper_pdf.should_close_file)
+            assert len(hopper_pdf.pages) == 1
+            assert hopper_pdf.should_close_buf
+            assert hopper_pdf.should_close_file
 
         # read a PDF file from a buffer with a non-zero offset
         with open(pdf_filename, "rb") as f:
             content = b"xyzzy" + f.read()
         with PdfParser.PdfParser(buf=content, start_offset=5) as hopper_pdf:
-            self.assertEqual(len(hopper_pdf.pages), 1)
-            self.assertFalse(hopper_pdf.should_close_buf)
-            self.assertFalse(hopper_pdf.should_close_file)
+            assert len(hopper_pdf.pages) == 1
+            assert not hopper_pdf.should_close_buf
+            assert not hopper_pdf.should_close_file
 
         # read a PDF file from an already open file
         with open(pdf_filename, "rb") as f:
             with PdfParser.PdfParser(f=f) as hopper_pdf:
-                self.assertEqual(len(hopper_pdf.pages), 1)
-                self.assertTrue(hopper_pdf.should_close_buf)
-                self.assertFalse(hopper_pdf.should_close_file)
+                assert len(hopper_pdf.pages) == 1
+                assert hopper_pdf.should_close_buf
+                assert not hopper_pdf.should_close_file
 
     def test_pdf_append_fails_on_nonexistent_file(self):
         im = hopper("RGB")
         with tempfile.TemporaryDirectory() as temp_dir:
-            self.assertRaises(
-                IOError, im.save, os.path.join(temp_dir, "nonexistent.pdf"), append=True
-            )
+            with pytest.raises(IOError):
+                im.save(os.path.join(temp_dir, "nonexistent.pdf"), append=True)
 
     def check_pdf_pages_consistency(self, pdf):
         pages_info = pdf.read_indirect(pdf.pages_ref)
-        self.assertNotIn(b"Parent", pages_info)
-        self.assertIn(b"Kids", pages_info)
+        assert b"Parent" not in pages_info
+        assert b"Kids" in pages_info
         kids_not_used = pages_info[b"Kids"]
         for page_ref in pdf.pages:
             while True:
                 if page_ref in kids_not_used:
                     kids_not_used.remove(page_ref)
                 page_info = pdf.read_indirect(page_ref)
-                self.assertIn(b"Parent", page_info)
+                assert b"Parent" in page_info
                 page_ref = page_info[b"Parent"]
                 if page_ref == pdf.pages_ref:
                     break
-            self.assertEqual(pdf.pages_ref, page_info[b"Parent"])
-        self.assertEqual(kids_not_used, [])
+            assert pdf.pages_ref == page_info[b"Parent"]
+        assert kids_not_used == []
 
     def test_pdf_append(self):
         # make a PDF file
@@ -190,14 +190,12 @@ class TestFilePdf(PillowTestCase):
 
         # open it, check pages and info
         with PdfParser.PdfParser(pdf_filename, mode="r+b") as pdf:
-            self.assertEqual(len(pdf.pages), 1)
-            self.assertEqual(len(pdf.info), 4)
-            self.assertEqual(
-                pdf.info.Title, os.path.splitext(os.path.basename(pdf_filename))[0]
-            )
-            self.assertEqual(pdf.info.Producer, "PdfParser")
-            self.assertIn(b"CreationDate", pdf.info)
-            self.assertIn(b"ModDate", pdf.info)
+            assert len(pdf.pages) == 1
+            assert len(pdf.info) == 4
+            assert pdf.info.Title == os.path.splitext(os.path.basename(pdf_filename))[0]
+            assert pdf.info.Producer == "PdfParser"
+            assert b"CreationDate" in pdf.info
+            assert b"ModDate" in pdf.info
             self.check_pdf_pages_consistency(pdf)
 
             # append some info
@@ -211,11 +209,11 @@ class TestFilePdf(PillowTestCase):
 
         # open it again, check pages and info again
         with PdfParser.PdfParser(pdf_filename) as pdf:
-            self.assertEqual(len(pdf.pages), 1)
-            self.assertEqual(len(pdf.info), 8)
-            self.assertEqual(pdf.info.Title, "abc")
-            self.assertIn(b"CreationDate", pdf.info)
-            self.assertIn(b"ModDate", pdf.info)
+            assert len(pdf.pages) == 1
+            assert len(pdf.info) == 8
+            assert pdf.info.Title == "abc"
+            assert b"CreationDate" in pdf.info
+            assert b"ModDate" in pdf.info
             self.check_pdf_pages_consistency(pdf)
 
         # append two images
@@ -225,15 +223,15 @@ class TestFilePdf(PillowTestCase):
 
         # open the PDF again, check pages and info again
         with PdfParser.PdfParser(pdf_filename) as pdf:
-            self.assertEqual(len(pdf.pages), 3)
-            self.assertEqual(len(pdf.info), 8)
-            self.assertEqual(PdfParser.decode_text(pdf.info[b"Title"]), "abc")
-            self.assertEqual(pdf.info.Title, "abc")
-            self.assertEqual(pdf.info.Producer, "PdfParser")
-            self.assertEqual(pdf.info.Keywords, "qw)e\\r(ty")
-            self.assertEqual(pdf.info.Subject, "ghi\uABCD")
-            self.assertIn(b"CreationDate", pdf.info)
-            self.assertIn(b"ModDate", pdf.info)
+            assert len(pdf.pages) == 3
+            assert len(pdf.info) == 8
+            assert PdfParser.decode_text(pdf.info[b"Title"]) == "abc"
+            assert pdf.info.Title == "abc"
+            assert pdf.info.Producer == "PdfParser"
+            assert pdf.info.Keywords == "qw)e\\r(ty"
+            assert pdf.info.Subject == "ghi\uABCD"
+            assert b"CreationDate" in pdf.info
+            assert b"ModDate" in pdf.info
             self.check_pdf_pages_consistency(pdf)
 
     def test_pdf_info(self):
@@ -252,15 +250,15 @@ class TestFilePdf(PillowTestCase):
 
         # open it, check pages and info
         with PdfParser.PdfParser(pdf_filename) as pdf:
-            self.assertEqual(len(pdf.info), 8)
-            self.assertEqual(pdf.info.Title, "title")
-            self.assertEqual(pdf.info.Author, "author")
-            self.assertEqual(pdf.info.Subject, "subject")
-            self.assertEqual(pdf.info.Keywords, "keywords")
-            self.assertEqual(pdf.info.Creator, "creator")
-            self.assertEqual(pdf.info.Producer, "producer")
-            self.assertEqual(pdf.info.CreationDate, time.strptime("2000", "%Y"))
-            self.assertEqual(pdf.info.ModDate, time.strptime("2001", "%Y"))
+            assert len(pdf.info) == 8
+            assert pdf.info.Title == "title"
+            assert pdf.info.Author == "author"
+            assert pdf.info.Subject == "subject"
+            assert pdf.info.Keywords == "keywords"
+            assert pdf.info.Creator == "creator"
+            assert pdf.info.Producer == "producer"
+            assert pdf.info.CreationDate == time.strptime("2000", "%Y")
+            assert pdf.info.ModDate == time.strptime("2001", "%Y")
             self.check_pdf_pages_consistency(pdf)
 
     def test_pdf_append_to_bytesio(self):
@@ -268,8 +266,8 @@ class TestFilePdf(PillowTestCase):
         f = io.BytesIO()
         im.save(f, format="PDF")
         initial_size = len(f.getvalue())
-        self.assertGreater(initial_size, 0)
+        assert initial_size > 0
         im = hopper("P")
         f = io.BytesIO(f.getvalue())
         im.save(f, format="PDF", append=True)
-        self.assertGreater(len(f.getvalue()), initial_size)
+        assert len(f.getvalue()) > initial_size

Tests/test_file_png.py

@@ -83,10 +83,10 @@ class TestFilePng(PillowTestCase):
 
         with Image.open(test_file) as im:
             im.load()
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "PNG")
-            self.assertEqual(im.get_format_mimetype(), "image/png")
+            assert im.mode == "RGB"
+            assert im.size == (128, 128)
+            assert im.format == "PNG"
+            assert im.get_format_mimetype() == "image/png"
 
         for mode in ["1", "L", "P", "RGB", "I", "I;16"]:
             im = hopper(mode)
@@ -99,112 +99,114 @@ class TestFilePng(PillowTestCase):
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, PngImagePlugin.PngImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            PngImagePlugin.PngImageFile(invalid_file)
 
     def test_broken(self):
         # Check reading of totally broken files.  In this case, the test
         # file was checked into Subversion as a text file.
 
         test_file = "Tests/images/broken.png"
-        self.assertRaises(IOError, Image.open, test_file)
+        with pytest.raises(IOError):
+            Image.open(test_file)
 
     def test_bad_text(self):
         # Make sure PIL can read malformed tEXt chunks (@PIL152)
 
         im = load(HEAD + chunk(b"tEXt") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"tEXt", b"spam") + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"tEXt", b"spam\0") + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"tEXt", b"spam\0egg") + TAIL)
-        self.assertEqual(im.info, {"spam": "egg"})
+        assert im.info == {"spam": "egg"}
 
         im = load(HEAD + chunk(b"tEXt", b"spam\0egg\0") + TAIL)
-        self.assertEqual(im.info, {"spam": "egg\x00"})
+        assert im.info == {"spam": "egg\x00"}
 
     def test_bad_ztxt(self):
         # Test reading malformed zTXt chunks (python-pillow/Pillow#318)
 
         im = load(HEAD + chunk(b"zTXt") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"zTXt", b"spam") + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"zTXt", b"spam\0") + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"zTXt", b"spam\0\0") + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"zTXt", b"spam\0\0" + zlib.compress(b"egg")[:1]) + TAIL)
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(HEAD + chunk(b"zTXt", b"spam\0\0" + zlib.compress(b"egg")) + TAIL)
-        self.assertEqual(im.info, {"spam": "egg"})
+        assert im.info == {"spam": "egg"}
 
     def test_bad_itxt(self):
 
         im = load(HEAD + chunk(b"iTXt") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"iTXt", b"spam") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"iTXt", b"spam\0") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"iTXt", b"spam\0\x02") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"iTXt", b"spam\0\0\0foo\0") + TAIL)
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(HEAD + chunk(b"iTXt", b"spam\0\0\0en\0Spam\0egg") + TAIL)
-        self.assertEqual(im.info, {"spam": "egg"})
-        self.assertEqual(im.info["spam"].lang, "en")
-        self.assertEqual(im.info["spam"].tkey, "Spam")
+        assert im.info == {"spam": "egg"}
+        assert im.info["spam"].lang == "en"
+        assert im.info["spam"].tkey == "Spam"
 
         im = load(
             HEAD
             + chunk(b"iTXt", b"spam\0\1\0en\0Spam\0" + zlib.compress(b"egg")[:1])
             + TAIL
         )
-        self.assertEqual(im.info, {"spam": ""})
+        assert im.info == {"spam": ""}
 
         im = load(
             HEAD
             + chunk(b"iTXt", b"spam\0\1\1en\0Spam\0" + zlib.compress(b"egg"))
             + TAIL
         )
-        self.assertEqual(im.info, {})
+        assert im.info == {}
 
         im = load(
             HEAD
             + chunk(b"iTXt", b"spam\0\1\0en\0Spam\0" + zlib.compress(b"egg"))
             + TAIL
         )
-        self.assertEqual(im.info, {"spam": "egg"})
-        self.assertEqual(im.info["spam"].lang, "en")
-        self.assertEqual(im.info["spam"].tkey, "Spam")
+        assert im.info == {"spam": "egg"}
+        assert im.info["spam"].lang == "en"
+        assert im.info["spam"].tkey == "Spam"
 
     def test_interlace(self):
 
         test_file = "Tests/images/pil123p.png"
         with Image.open(test_file) as im:
             assert_image(im, "P", (162, 150))
-            self.assertTrue(im.info.get("interlace"))
+            assert im.info.get("interlace")
 
             im.load()
 
         test_file = "Tests/images/pil123rgba.png"
         with Image.open(test_file) as im:
             assert_image(im, "RGBA", (162, 150))
-            self.assertTrue(im.info.get("interlace"))
+            assert im.info.get("interlace")
 
             im.load()
 
@@ -216,69 +218,69 @@ class TestFilePng(PillowTestCase):
         assert_image(im, "RGBA", (162, 150))
 
         # image has 124 unique alpha values
-        self.assertEqual(len(im.getchannel("A").getcolors()), 124)
+        assert len(im.getchannel("A").getcolors()) == 124
 
     def test_load_transparent_rgb(self):
         test_file = "Tests/images/rgb_trns.png"
         with Image.open(test_file) as im:
-            self.assertEqual(im.info["transparency"], (0, 255, 52))
+            assert im.info["transparency"] == (0, 255, 52)
 
             assert_image(im, "RGB", (64, 64))
             im = im.convert("RGBA")
         assert_image(im, "RGBA", (64, 64))
 
         # image has 876 transparent pixels
-        self.assertEqual(im.getchannel("A").getcolors()[0][0], 876)
+        assert im.getchannel("A").getcolors()[0][0] == 876
 
     def test_save_p_transparent_palette(self):
         in_file = "Tests/images/pil123p.png"
         with Image.open(in_file) as im:
             # 'transparency' contains a byte string with the opacity for
             # each palette entry
-            self.assertEqual(len(im.info["transparency"]), 256)
+            assert len(im.info["transparency"]) == 256
 
             test_file = self.tempfile("temp.png")
             im.save(test_file)
 
         # check if saved image contains same transparency
         with Image.open(test_file) as im:
-            self.assertEqual(len(im.info["transparency"]), 256)
+            assert len(im.info["transparency"]) == 256
 
             assert_image(im, "P", (162, 150))
             im = im.convert("RGBA")
         assert_image(im, "RGBA", (162, 150))
 
         # image has 124 unique alpha values
-        self.assertEqual(len(im.getchannel("A").getcolors()), 124)
+        assert len(im.getchannel("A").getcolors()) == 124
 
     def test_save_p_single_transparency(self):
         in_file = "Tests/images/p_trns_single.png"
         with Image.open(in_file) as im:
             # pixel value 164 is full transparent
-            self.assertEqual(im.info["transparency"], 164)
-            self.assertEqual(im.getpixel((31, 31)), 164)
+            assert im.info["transparency"] == 164
+            assert im.getpixel((31, 31)) == 164
 
             test_file = self.tempfile("temp.png")
             im.save(test_file)
 
         # check if saved image contains same transparency
         with Image.open(test_file) as im:
-            self.assertEqual(im.info["transparency"], 164)
-            self.assertEqual(im.getpixel((31, 31)), 164)
+            assert im.info["transparency"] == 164
+            assert im.getpixel((31, 31)) == 164
             assert_image(im, "P", (64, 64))
             im = im.convert("RGBA")
         assert_image(im, "RGBA", (64, 64))
 
-        self.assertEqual(im.getpixel((31, 31)), (0, 255, 52, 0))
+        assert im.getpixel((31, 31)) == (0, 255, 52, 0)
 
         # image has 876 transparent pixels
-        self.assertEqual(im.getchannel("A").getcolors()[0][0], 876)
+        assert im.getchannel("A").getcolors()[0][0] == 876
 
     def test_save_p_transparent_black(self):
         # check if solid black image with full transparency
         # is supported (check for #1838)
         im = Image.new("RGBA", (10, 10), (0, 0, 0, 0))
-        self.assertEqual(im.getcolors(), [(100, (0, 0, 0, 0))])
+        assert im.getcolors() == [(100, (0, 0, 0, 0))]
 
         im = im.convert("P")
         test_file = self.tempfile("temp.png")
@@ -286,34 +288,32 @@ class TestFilePng(PillowTestCase):
 
         # check if saved image contains same transparency
         with Image.open(test_file) as im:
-            self.assertEqual(len(im.info["transparency"]), 256)
+            assert len(im.info["transparency"]) == 256
             assert_image(im, "P", (10, 10))
             im = im.convert("RGBA")
         assert_image(im, "RGBA", (10, 10))
-        self.assertEqual(im.getcolors(), [(100, (0, 0, 0, 0))])
+        assert im.getcolors() == [(100, (0, 0, 0, 0))]
 
     def test_save_greyscale_transparency(self):
         for mode, num_transparent in {"1": 1994, "L": 559, "I": 559}.items():
             in_file = "Tests/images/" + mode.lower() + "_trns.png"
             with Image.open(in_file) as im:
-                self.assertEqual(im.mode, mode)
-                self.assertEqual(im.info["transparency"], 255)
+                assert im.mode == mode
+                assert im.info["transparency"] == 255
 
                 im_rgba = im.convert("RGBA")
-            self.assertEqual(im_rgba.getchannel("A").getcolors()[0][0], num_transparent)
+            assert im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
 
             test_file = self.tempfile("temp.png")
             im.save(test_file)
 
             with Image.open(test_file) as test_im:
-                self.assertEqual(test_im.mode, mode)
-                self.assertEqual(test_im.info["transparency"], 255)
+                assert test_im.mode == mode
+                assert test_im.info["transparency"] == 255
                 assert_image_equal(im, test_im)
 
             test_im_rgba = test_im.convert("RGBA")
-            self.assertEqual(
-                test_im_rgba.getchannel("A").getcolors()[0][0], num_transparent
-            )
+            assert test_im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
 
     def test_save_rgb_single_transparency(self):
         in_file = "Tests/images/caption_6_33_22.png"
@@ -330,7 +330,8 @@ class TestFilePng(PillowTestCase):
 
         with Image.open(TEST_PNG_FILE) as im:
             im.load()
-            self.assertRaises(RuntimeError, im.verify)
+            with pytest.raises(RuntimeError):
+                im.verify()
 
     def test_verify_struct_error(self):
         # Check open/load/verify exception (#1755)
@@ -344,8 +345,9 @@ class TestFilePng(PillowTestCase):
                 test_file = f.read()[:offset]
 
             with Image.open(BytesIO(test_file)) as im:
-                self.assertIsNotNone(im.fp)
-                self.assertRaises((IOError, SyntaxError), im.verify)
+                assert im.fp is not None
+                with pytest.raises((IOError, SyntaxError)):
+                    im.verify()
 
     def test_verify_ignores_crc_error(self):
         # check ignores crc errors in ancillary chunks
@@ -354,12 +356,13 @@ class TestFilePng(PillowTestCase):
         broken_crc_chunk_data = chunk_data[:-1] + b"q"  # break CRC
 
         image_data = HEAD + broken_crc_chunk_data + TAIL
-        self.assertRaises(SyntaxError, PngImagePlugin.PngImageFile, BytesIO(image_data))
+        with pytest.raises(SyntaxError):
+            PngImagePlugin.PngImageFile(BytesIO(image_data))
 
         ImageFile.LOAD_TRUNCATED_IMAGES = True
         try:
             im = load(image_data)
-            self.assertIsNotNone(im)
+            assert im is not None
         finally:
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
@@ -370,9 +373,8 @@ class TestFilePng(PillowTestCase):
 
         ImageFile.LOAD_TRUNCATED_IMAGES = True
         try:
-            self.assertRaises(
-                SyntaxError, PngImagePlugin.PngImageFile, BytesIO(image_data)
-            )
+            with pytest.raises(SyntaxError):
+                PngImagePlugin.PngImageFile(BytesIO(image_data))
         finally:
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
@@ -381,24 +383,24 @@ class TestFilePng(PillowTestCase):
 
         with Image.open(TEST_PNG_FILE) as im:
             im = roundtrip(im, dpi=(100, 100))
-        self.assertEqual(im.info["dpi"], (100, 100))
+        assert im.info["dpi"] == (100, 100)
 
     def test_load_dpi_rounding(self):
         # Round up
         with Image.open(TEST_PNG_FILE) as im:
-            self.assertEqual(im.info["dpi"], (96, 96))
+            assert im.info["dpi"] == (96, 96)
 
         # Round down
         with Image.open("Tests/images/icc_profile_none.png") as im:
-            self.assertEqual(im.info["dpi"], (72, 72))
+            assert im.info["dpi"] == (72, 72)
 
     def test_save_dpi_rounding(self):
         with Image.open(TEST_PNG_FILE) as im:
             im = roundtrip(im, dpi=(72.2, 72.2))
-        self.assertEqual(im.info["dpi"], (72, 72))
+        assert im.info["dpi"] == (72, 72)
 
         im = roundtrip(im, dpi=(72.8, 72.8))
-        self.assertEqual(im.info["dpi"], (73, 73))
+        assert im.info["dpi"] == (73, 73)
 
     def test_roundtrip_text(self):
         # Check text roundtripping
@@ -409,8 +411,8 @@ class TestFilePng(PillowTestCase):
             info.add_text("ZIP", "VALUE", zip=True)
 
             im = roundtrip(im, pnginfo=info)
-        self.assertEqual(im.info, {"TXT": "VALUE", "ZIP": "VALUE"})
-        self.assertEqual(im.text, {"TXT": "VALUE", "ZIP": "VALUE"})
+        assert im.info == {"TXT": "VALUE", "ZIP": "VALUE"}
+        assert im.text == {"TXT": "VALUE", "ZIP": "VALUE"}
 
     def test_roundtrip_itxt(self):
         # Check iTXt roundtripping
@@ -421,12 +423,12 @@ class TestFilePng(PillowTestCase):
         info.add_text("eggs", PngImagePlugin.iTXt("Spam", "en", "Eggs"), zip=True)
 
         im = roundtrip(im, pnginfo=info)
-        self.assertEqual(im.info, {"spam": "Eggs", "eggs": "Spam"})
-        self.assertEqual(im.text, {"spam": "Eggs", "eggs": "Spam"})
-        self.assertEqual(im.text["spam"].lang, "en")
-        self.assertEqual(im.text["spam"].tkey, "Spam")
-        self.assertEqual(im.text["eggs"].lang, "en")
-        self.assertEqual(im.text["eggs"].tkey, "Eggs")
+        assert im.info == {"spam": "Eggs", "eggs": "Spam"}
+        assert im.text == {"spam": "Eggs", "eggs": "Spam"}
+        assert im.text["spam"].lang == "en"
+        assert im.text["spam"].tkey == "Spam"
+        assert im.text["eggs"].lang == "en"
+        assert im.text["eggs"].tkey == "Eggs"
 
     def test_nonunicode_text(self):
         # Check so that non-Unicode text is saved as a tEXt rather than iTXt
@@ -435,7 +437,7 @@ class TestFilePng(PillowTestCase):
         info = PngImagePlugin.PngInfo()
         info.add_text("Text", "Ascii")
         im = roundtrip(im, pnginfo=info)
-        self.assertIsInstance(im.info["Text"], str)
+        assert isinstance(im.info["Text"], str)
 
     def test_unicode_text(self):
         # Check preservation of non-ASCII characters
@@ -445,7 +447,7 @@ class TestFilePng(PillowTestCase):
             info = PngImagePlugin.PngInfo()
             info.add_text("Text", value)
             im = roundtrip(im, pnginfo=info)
-            self.assertEqual(im.info, {"Text": value})
+            assert im.info == {"Text": value}
 
         rt_text(" Aa" + chr(0xA0) + chr(0xC4) + chr(0xFF))  # Latin1
         rt_text(chr(0x400) + chr(0x472) + chr(0x4FF))  # Cyrillic
@@ -463,7 +465,8 @@ class TestFilePng(PillowTestCase):
             data = b"\x89" + fd.read()
 
         pngfile = BytesIO(data)
-        self.assertRaises(IOError, Image.open, pngfile)
+        with pytest.raises(IOError):
+            Image.open(pngfile)
 
     def test_trns_rgb(self):
         # Check writing and reading of tRNS chunks for RGB images.
@@ -471,14 +474,14 @@ class TestFilePng(PillowTestCase):
 
         test_file = "Tests/images/caption_6_33_22.png"
         with Image.open(test_file) as im:
-            self.assertEqual(im.info["transparency"], (248, 248, 248))
+            assert im.info["transparency"] == (248, 248, 248)
 
             # check saving transparency by default
             im = roundtrip(im)
-        self.assertEqual(im.info["transparency"], (248, 248, 248))
+        assert im.info["transparency"] == (248, 248, 248)
 
         im = roundtrip(im, transparency=(0, 1, 2))
-        self.assertEqual(im.info["transparency"], (0, 1, 2))
+        assert im.info["transparency"] == (0, 1, 2)
 
     def test_trns_p(self):
         # Check writing a transparency of 0, issue #528
@@ -489,7 +492,7 @@ class TestFilePng(PillowTestCase):
         im.save(f)
 
         with Image.open(f) as im2:
-            self.assertIn("transparency", im2.info)
+            assert "transparency" in im2.info
 
             assert_image_equal(im2.convert("RGBA"), im.convert("RGBA"))
 
@@ -498,42 +501,42 @@ class TestFilePng(PillowTestCase):
         test_file = "Tests/images/tRNS_null_1x1.png"
         with Image.open(test_file) as im:
 
-            self.assertEqual(im.info["transparency"], 0)
+            assert im.info["transparency"] == 0
 
     def test_save_icc_profile(self):
         with Image.open("Tests/images/icc_profile_none.png") as im:
-            self.assertIsNone(im.info["icc_profile"])
+            assert im.info["icc_profile"] is None
 
             with Image.open("Tests/images/icc_profile.png") as with_icc:
                 expected_icc = with_icc.info["icc_profile"]
 
                 im = roundtrip(im, icc_profile=expected_icc)
-                self.assertEqual(im.info["icc_profile"], expected_icc)
+                assert im.info["icc_profile"] == expected_icc
 
     def test_discard_icc_profile(self):
         with Image.open("Tests/images/icc_profile.png") as im:
             im = roundtrip(im, icc_profile=None)
-        self.assertNotIn("icc_profile", im.info)
+        assert "icc_profile" not in im.info
 
     def test_roundtrip_icc_profile(self):
         with Image.open("Tests/images/icc_profile.png") as im:
             expected_icc = im.info["icc_profile"]
 
             im = roundtrip(im)
-        self.assertEqual(im.info["icc_profile"], expected_icc)
+        assert im.info["icc_profile"] == expected_icc
 
     def test_roundtrip_no_icc_profile(self):
         with Image.open("Tests/images/icc_profile_none.png") as im:
-            self.assertIsNone(im.info["icc_profile"])
+            assert im.info["icc_profile"] is None
 
             im = roundtrip(im)
-        self.assertNotIn("icc_profile", im.info)
+        assert "icc_profile" not in im.info
 
     def test_repr_png(self):
         im = hopper()
 
         with Image.open(BytesIO(im._repr_png_())) as repr_png:
-            self.assertEqual(repr_png.format, "PNG")
+            assert repr_png.format == "PNG"
             assert_image_equal(im, repr_png)
 
     def test_chunk_order(self):
@@ -545,54 +548,55 @@ class TestFilePng(PillowTestCase):
 
         # https://www.w3.org/TR/PNG/#5ChunkOrdering
         # IHDR - shall be first
-        self.assertEqual(chunks.index(b"IHDR"), 0)
+        assert chunks.index(b"IHDR") == 0
         # PLTE - before first IDAT
-        self.assertLess(chunks.index(b"PLTE"), chunks.index(b"IDAT"))
+        assert chunks.index(b"PLTE") < chunks.index(b"IDAT")
         # iCCP - before PLTE and IDAT
-        self.assertLess(chunks.index(b"iCCP"), chunks.index(b"PLTE"))
-        self.assertLess(chunks.index(b"iCCP"), chunks.index(b"IDAT"))
+        assert chunks.index(b"iCCP") < chunks.index(b"PLTE")
+        assert chunks.index(b"iCCP") < chunks.index(b"IDAT")
         # tRNS - after PLTE, before IDAT
-        self.assertGreater(chunks.index(b"tRNS"), chunks.index(b"PLTE"))
-        self.assertLess(chunks.index(b"tRNS"), chunks.index(b"IDAT"))
+        assert chunks.index(b"tRNS") > chunks.index(b"PLTE")
+        assert chunks.index(b"tRNS") < chunks.index(b"IDAT")
         # pHYs - before IDAT
-        self.assertLess(chunks.index(b"pHYs"), chunks.index(b"IDAT"))
+        assert chunks.index(b"pHYs") < chunks.index(b"IDAT")
 
     def test_getchunks(self):
         im = hopper()
 
         chunks = PngImagePlugin.getchunks(im)
-        self.assertEqual(len(chunks), 3)
+        assert len(chunks) == 3
 
     def test_textual_chunks_after_idat(self):
         with Image.open("Tests/images/hopper.png") as im:
-            self.assertIn("comment", im.text.keys())
+            assert "comment" in im.text.keys()
             for k, v in {
                 "date:create": "2014-09-04T09:37:08+03:00",
                 "date:modify": "2014-09-04T09:37:08+03:00",
             }.items():
-                self.assertEqual(im.text[k], v)
+                assert im.text[k] == v
 
         # Raises a SyntaxError in load_end
         with Image.open("Tests/images/broken_data_stream.png") as im:
-            with self.assertRaises(IOError):
-                self.assertIsInstance(im.text, dict)
+            with pytest.raises(IOError):
+                assert isinstance(im.text, dict)
 
         # Raises a UnicodeDecodeError in load_end
         with Image.open("Tests/images/truncated_image.png") as im:
             # The file is truncated
-            self.assertRaises(IOError, lambda: im.text)
+            with pytest.raises(IOError):
+                im.text()
             ImageFile.LOAD_TRUNCATED_IMAGES = True
-            self.assertIsInstance(im.text, dict)
+            assert isinstance(im.text, dict)
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
         # Raises an EOFError in load_end
         with Image.open("Tests/images/hopper_idat_after_image_end.png") as im:
-            self.assertEqual(im.text, {"TXT": "VALUE", "ZIP": "VALUE"})
+            assert im.text == {"TXT": "VALUE", "ZIP": "VALUE"}
 
     def test_exif(self):
         with Image.open("Tests/images/exif.png") as im:
             exif = im._getexif()
-        self.assertEqual(exif[274], 1)
+        assert exif[274] == 1
 
     def test_exif_save(self):
         with Image.open("Tests/images/exif.png") as im:
@@ -601,7 +605,7 @@ class TestFilePng(PillowTestCase):
 
         with Image.open(test_file) as reloaded:
             exif = reloaded._getexif()
-        self.assertEqual(exif[274], 1)
+        assert exif[274] == 1
 
     def test_exif_from_jpg(self):
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
@@ -610,7 +614,7 @@ class TestFilePng(PillowTestCase):
 
         with Image.open(test_file) as reloaded:
             exif = reloaded._getexif()
-        self.assertEqual(exif[305], "Adobe Photoshop CS Macintosh")
+        assert exif[305] == "Adobe Photoshop CS Macintosh"
 
     def test_exif_argument(self):
         with Image.open(TEST_PNG_FILE) as im:
@@ -618,13 +622,13 @@ class TestFilePng(PillowTestCase):
             im.save(test_file, exif=b"exifstring")
 
         with Image.open(test_file) as reloaded:
-            self.assertEqual(reloaded.info["exif"], b"Exif\x00\x00exifstring")
+            assert reloaded.info["exif"] == b"Exif\x00\x00exifstring"
 
     @skip_unless_feature("webp")
     @skip_unless_feature("webp_anim")
     def test_apng(self):
         with Image.open("Tests/images/iss634.apng") as im:
-            self.assertEqual(im.get_format_mimetype(), "image/apng")
+            assert im.get_format_mimetype() == "image/apng"
 
             # This also tests reading unknown PNG chunks (fcTL and fdAT) in load_end
             with Image.open("Tests/images/iss634.webp") as expected:

Tests/test_file_ppm.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image
 
 from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
@@ -10,17 +11,17 @@ class TestFilePpm(PillowTestCase):
     def test_sanity(self):
         with Image.open(test_file) as im:
             im.load()
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "PPM")
-            self.assertEqual(im.get_format_mimetype(), "image/x-portable-pixmap")
+            assert im.mode == "RGB"
+            assert im.size == (128, 128)
+            assert im.format, "PPM"
+            assert im.get_format_mimetype() == "image/x-portable-pixmap"
 
     def test_16bit_pgm(self):
         with Image.open("Tests/images/16_bit_binary.pgm") as im:
             im.load()
-            self.assertEqual(im.mode, "I")
-            self.assertEqual(im.size, (20, 100))
-            self.assertEqual(im.get_format_mimetype(), "image/x-portable-graymap")
+            assert im.mode == "I"
+            assert im.size == (20, 100)
+            assert im.get_format_mimetype() == "image/x-portable-graymap"
 
             with Image.open("Tests/images/16_bit_binary_pgm.png") as tgt:
                 assert_image_equal(im, tgt)
@@ -50,7 +51,8 @@ class TestFilePpm(PillowTestCase):
         with open(path, "w") as f:
             f.write("P6")
 
-        self.assertRaises(ValueError, Image.open, path)
+        with pytest.raises(ValueError):
+            Image.open(path)
 
     def test_neg_ppm(self):
         # Storage.c accepted negative values for xsize, ysize.  the
@@ -58,7 +60,7 @@ class TestFilePpm(PillowTestCase):
         # has been removed. The default opener doesn't accept negative
         # sizes.
 
-        with self.assertRaises(IOError):
+        with pytest.raises(IOError):
             Image.open("Tests/images/negative_size.ppm")
 
     def test_mimetypes(self):
@@ -67,9 +69,9 @@ class TestFilePpm(PillowTestCase):
         with open(path, "w") as f:
             f.write("P4\n128 128\n255")
         with Image.open(path) as im:
-            self.assertEqual(im.get_format_mimetype(), "image/x-portable-bitmap")
+            assert im.get_format_mimetype() == "image/x-portable-bitmap"
 
         with open(path, "w") as f:
             f.write("PyCMYK\n128 128\n255")
         with Image.open(path) as im:
-            self.assertEqual(im.get_format_mimetype(), "image/x-portable-anymap")
+            assert im.get_format_mimetype() == "image/x-portable-anymap"

Tests/test_file_sgi.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, SgiImagePlugin
 
 from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
@@ -11,7 +12,7 @@ class TestFileSgi(PillowTestCase):
 
         with Image.open(test_file) as im:
             assert_image_equal(im, hopper())
-            self.assertEqual(im.get_format_mimetype(), "image/rgb")
+            assert im.get_format_mimetype() == "image/rgb"
 
     def test_rgb16(self):
         test_file = "Tests/images/hopper16.rgb"
@@ -26,7 +27,7 @@ class TestFileSgi(PillowTestCase):
 
         with Image.open(test_file) as im:
             assert_image_similar(im, hopper("L"), 2)
-            self.assertEqual(im.get_format_mimetype(), "image/sgi")
+            assert im.get_format_mimetype() == "image/sgi"
 
     def test_rgba(self):
         # Created with ImageMagick:
@@ -36,7 +37,7 @@ class TestFileSgi(PillowTestCase):
         with Image.open(test_file) as im:
             with Image.open("Tests/images/transparent.png") as target:
                 assert_image_equal(im, target)
-            self.assertEqual(im.get_format_mimetype(), "image/sgi")
+            assert im.get_format_mimetype() == "image/sgi"
 
     def test_rle(self):
         # Created with ImageMagick:
@@ -57,7 +58,8 @@ class TestFileSgi(PillowTestCase):
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(ValueError, SgiImagePlugin.SgiImageFile, invalid_file)
+        with pytest.raises(ValueError):
+            SgiImagePlugin.SgiImageFile(invalid_file)
 
     def test_write(self):
         def roundtrip(img):
@@ -86,4 +88,5 @@ class TestFileSgi(PillowTestCase):
         im = hopper("LA")
         out = self.tempfile("temp.sgi")
 
-        self.assertRaises(ValueError, im.save, out, format="sgi")
+        with pytest.raises(ValueError):
+            im.save(out, format="sgi")

Tests/test_file_spider.py

@@ -14,9 +14,9 @@ class TestImageSpider(PillowTestCase):
     def test_sanity(self):
         with Image.open(TEST_FILE) as im:
             im.load()
-            self.assertEqual(im.mode, "F")
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.format, "SPIDER")
+            assert im.mode == "F"
+            assert im.size == (128, 128)
+            assert im.format == "SPIDER"
 
     @unittest.skipIf(is_pypy(), "Requires CPython")
     def test_unclosed_file(self):
@@ -51,9 +51,9 @@ class TestImageSpider(PillowTestCase):
 
         # Assert
         with Image.open(temp) as im2:
-            self.assertEqual(im2.mode, "F")
-            self.assertEqual(im2.size, (128, 128))
-            self.assertEqual(im2.format, "SPIDER")
+            assert im2.mode == "F"
+            assert im2.size == (128, 128)
+            assert im2.format == "SPIDER"
 
     def test_tempfile(self):
         # Arrange
@@ -66,12 +66,12 @@ class TestImageSpider(PillowTestCase):
             # Assert
             fp.seek(0)
             with Image.open(fp) as reloaded:
-                self.assertEqual(reloaded.mode, "F")
-                self.assertEqual(reloaded.size, (128, 128))
-                self.assertEqual(reloaded.format, "SPIDER")
+                assert reloaded.mode == "F"
+                assert reloaded.size == (128, 128)
+                assert reloaded.format == "SPIDER"
 
     def test_isSpiderImage(self):
-        self.assertTrue(SpiderImagePlugin.isSpiderImage(TEST_FILE))
+        assert SpiderImagePlugin.isSpiderImage(TEST_FILE)
 
     def test_tell(self):
         # Arrange
@@ -81,12 +81,12 @@ class TestImageSpider(PillowTestCase):
             index = im.tell()
 
             # Assert
-            self.assertEqual(index, 0)
+            assert index == 0
 
     def test_n_frames(self):
         with Image.open(TEST_FILE) as im:
-            self.assertEqual(im.n_frames, 1)
-            self.assertFalse(im.is_animated)
+            assert im.n_frames == 1
+            assert not im.is_animated
 
     def test_loadImageSeries(self):
         # Arrange
@@ -97,9 +97,9 @@ class TestImageSpider(PillowTestCase):
         img_list = SpiderImagePlugin.loadImageSeries(file_list)
 
         # Assert
-        self.assertEqual(len(img_list), 1)
-        self.assertIsInstance(img_list[0], Image.Image)
-        self.assertEqual(img_list[0].size, (128, 128))
+        assert len(img_list) == 1
+        assert isinstance(img_list[0], Image.Image)
+        assert img_list[0].size == (128, 128)
 
     def test_loadImageSeries_no_input(self):
         # Arrange
@@ -109,7 +109,7 @@ class TestImageSpider(PillowTestCase):
         img_list = SpiderImagePlugin.loadImageSeries(file_list)
 
         # Assert
-        self.assertIsNone(img_list)
+        assert img_list is None
 
     def test_isInt_not_a_number(self):
         # Arrange
@@ -119,21 +119,23 @@ class TestImageSpider(PillowTestCase):
         ret = SpiderImagePlugin.isInt(not_a_number)
 
         # Assert
-        self.assertEqual(ret, 0)
+        assert ret == 0
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/invalid.spider"
 
-        self.assertRaises(IOError, Image.open, invalid_file)
+        with pytest.raises(IOError):
+            Image.open(invalid_file)
 
     def test_nonstack_file(self):
         with Image.open(TEST_FILE) as im:
-            self.assertRaises(EOFError, im.seek, 0)
+            with pytest.raises(EOFError):
+                im.seek(0)
 
     def test_nonstack_dos(self):
         with Image.open(TEST_FILE) as im:
             for i, frame in enumerate(ImageSequence.Iterator(im)):
-                self.assertLessEqual(i, 1, "Non-stack DOS file test failed")
+                assert i <= 1, "Non-stack DOS file test failed"
 
     # for issue #4093
     def test_odd_size(self):

Tests/test_file_tga.py

@@ -26,7 +26,7 @@ class TestFileTga(PillowTestCase):
 
             for png_path in png_paths:
                 with Image.open(png_path) as reference_im:
-                    self.assertEqual(reference_im.mode, mode)
+                    assert reference_im.mode == mode
 
                     path_no_ext = os.path.splitext(png_path)[0]
                     for origin, rle in product(self._ORIGINS, (True, False)):
@@ -35,21 +35,18 @@ class TestFileTga(PillowTestCase):
                         )
 
                         with Image.open(tga_path) as original_im:
-                            self.assertEqual(original_im.format, "TGA")
-                            self.assertEqual(
-                                original_im.get_format_mimetype(), "image/x-tga"
-                            )
+                            assert original_im.format == "TGA"
+                            assert original_im.get_format_mimetype() == "image/x-tga"
                             if rle:
-                                self.assertEqual(
-                                    original_im.info["compression"], "tga_rle"
-                                )
-                            self.assertEqual(
-                                original_im.info["orientation"],
-                                self._ORIGIN_TO_ORIENTATION[origin],
+                                assert original_im.info["compression"] == "tga_rle"
+                            assert (
+                                original_im.info["orientation"]
+                                == self._ORIGIN_TO_ORIENTATION[origin]
                             )
                             if mode == "P":
-                                self.assertEqual(
-                                    original_im.getpalette(), reference_im.getpalette()
+                                assert (
+                                    original_im.getpalette()
+                                    == reference_im.getpalette()
                                 )
 
                             assert_image_equal(original_im, reference_im)
@@ -62,17 +59,18 @@ class TestFileTga(PillowTestCase):
                             original_im.save(out, rle=rle)
                             with Image.open(out) as saved_im:
                                 if rle:
-                                    self.assertEqual(
-                                        saved_im.info["compression"],
-                                        original_im.info["compression"],
+                                    assert (
+                                        saved_im.info["compression"]
+                                        == original_im.info["compression"]
                                     )
-                                self.assertEqual(
-                                    saved_im.info["orientation"],
-                                    original_im.info["orientation"],
+                                assert (
+                                    saved_im.info["orientation"]
+                                    == original_im.info["orientation"]
                                 )
                                 if mode == "P":
-                                    self.assertEqual(
-                                        saved_im.getpalette(), original_im.getpalette()
+                                    assert (
+                                        saved_im.getpalette()
+                                        == original_im.getpalette()
                                     )
 
                                 assert_image_equal(saved_im, original_im)
@@ -85,7 +83,7 @@ class TestFileTga(PillowTestCase):
         with Image.open(test_file) as im:
 
             # Assert
-            self.assertEqual(im.size, (100, 100))
+            assert im.size == (100, 100)
 
     def test_id_field_rle(self):
         # tga file with id field
@@ -95,7 +93,7 @@ class TestFileTga(PillowTestCase):
         with Image.open(test_file) as im:
 
             # Assert
-            self.assertEqual(im.size, (199, 199))
+            assert im.size == (199, 199)
 
     def test_save(self):
         test_file = "Tests/images/tga_id_field.tga"
@@ -105,19 +103,19 @@ class TestFileTga(PillowTestCase):
             # Save
             im.save(out)
             with Image.open(out) as test_im:
-                self.assertEqual(test_im.size, (100, 100))
-                self.assertEqual(test_im.info["id_section"], im.info["id_section"])
+                assert test_im.size == (100, 100)
+                assert test_im.info["id_section"] == im.info["id_section"]
 
             # RGBA save
             im.convert("RGBA").save(out)
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.size, (100, 100))
+            assert test_im.size == (100, 100)
 
     def test_save_wrong_mode(self):
         im = hopper("PA")
         out = self.tempfile("temp.tga")
 
-        with self.assertRaises(OSError):
+        with pytest.raises(OSError):
             im.save(out)
 
     def test_save_id_section(self):
@@ -128,18 +126,18 @@ class TestFileTga(PillowTestCase):
             # Check there is no id section
             im.save(out)
         with Image.open(out) as test_im:
-            self.assertNotIn("id_section", test_im.info)
+            assert "id_section" not in test_im.info
 
         # Save with custom id section
         im.save(out, id_section=b"Test content")
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.info["id_section"], b"Test content")
+            assert test_im.info["id_section"] == b"Test content"
 
         # Save with custom id section greater than 255 characters
         id_section = b"Test content" * 25
         pytest.warns(UserWarning, lambda: im.save(out, id_section=id_section))
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.info["id_section"], id_section[:255])
+            assert test_im.info["id_section"] == id_section[:255]
 
         test_file = "Tests/images/tga_id_field.tga"
         with Image.open(test_file) as im:
@@ -147,49 +145,49 @@ class TestFileTga(PillowTestCase):
             # Save with no id section
             im.save(out, id_section="")
         with Image.open(out) as test_im:
-            self.assertNotIn("id_section", test_im.info)
+            assert "id_section" not in test_im.info
 
     def test_save_orientation(self):
         test_file = "Tests/images/rgb32rle.tga"
         out = self.tempfile("temp.tga")
         with Image.open(test_file) as im:
-            self.assertEqual(im.info["orientation"], -1)
+            assert im.info["orientation"] == -1
 
             im.save(out, orientation=1)
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.info["orientation"], 1)
+            assert test_im.info["orientation"] == 1
 
     def test_save_rle(self):
         test_file = "Tests/images/rgb32rle.tga"
         with Image.open(test_file) as im:
-            self.assertEqual(im.info["compression"], "tga_rle")
+            assert im.info["compression"] == "tga_rle"
 
             out = self.tempfile("temp.tga")
 
             # Save
             im.save(out)
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.size, (199, 199))
-            self.assertEqual(test_im.info["compression"], "tga_rle")
+            assert test_im.size == (199, 199)
+            assert test_im.info["compression"] == "tga_rle"
 
         # Save without compression
         im.save(out, compression=None)
         with Image.open(out) as test_im:
-            self.assertNotIn("compression", test_im.info)
+            assert "compression" not in test_im.info
 
         # RGBA save
         im.convert("RGBA").save(out)
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.size, (199, 199))
+            assert test_im.size == (199, 199)
 
         test_file = "Tests/images/tga_id_field.tga"
         with Image.open(test_file) as im:
-            self.assertNotIn("compression", im.info)
+            assert "compression" not in im.info
 
             # Save with compression
             im.save(out, compression="tga_rle")
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.info["compression"], "tga_rle")
+            assert test_im.info["compression"] == "tga_rle"
 
     def test_save_l_transparency(self):
         # There are 559 transparent pixels in la.tga.
@@ -197,14 +195,14 @@ class TestFileTga(PillowTestCase):
 
         in_file = "Tests/images/la.tga"
         with Image.open(in_file) as im:
-            self.assertEqual(im.mode, "LA")
-            self.assertEqual(im.getchannel("A").getcolors()[0][0], num_transparent)
+            assert im.mode == "LA"
+            assert im.getchannel("A").getcolors()[0][0] == num_transparent
 
             out = self.tempfile("temp.tga")
             im.save(out)
 
         with Image.open(out) as test_im:
-            self.assertEqual(test_im.mode, "LA")
-            self.assertEqual(test_im.getchannel("A").getcolors()[0][0], num_transparent)
+            assert test_im.mode == "LA"
+            assert test_im.getchannel("A").getcolors()[0][0] == num_transparent
 
             assert_image_equal(im, test_im)

Tests/test_file_tiff.py

@@ -30,9 +30,9 @@ class TestFileTiff(PillowTestCase):
 
         with Image.open(filename) as im:
             im.load()
-        self.assertEqual(im.mode, "RGB")
-        self.assertEqual(im.size, (128, 128))
-        self.assertEqual(im.format, "TIFF")
+        assert im.mode == "RGB"
+        assert im.size == (128, 128)
+        assert im.format == "TIFF"
 
         hopper("1").save(filename)
         with Image.open(filename):
@@ -82,53 +82,54 @@ class TestFileTiff(PillowTestCase):
 
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (55, 43))
-            self.assertEqual(im.tile, [("raw", (0, 0, 55, 43), 8, ("RGBa", 0, 1))])
+            assert im.mode == "RGBA"
+            assert im.size == (55, 43)
+            assert im.tile == [("raw", (0, 0, 55, 43), 8, ("RGBa", 0, 1))]
             im.load()
 
             assert_image_similar_tofile(im, "Tests/images/pil136.png", 1)
 
     def test_wrong_bits_per_sample(self):
         with Image.open("Tests/images/tiff_wrong_bits_per_sample.tiff") as im:
-            self.assertEqual(im.mode, "RGBA")
-            self.assertEqual(im.size, (52, 53))
-            self.assertEqual(im.tile, [("raw", (0, 0, 52, 53), 160, ("RGBA", 0, 1))])
+            assert im.mode == "RGBA"
+            assert im.size == (52, 53)
+            assert im.tile == [("raw", (0, 0, 52, 53), 160, ("RGBA", 0, 1))]
             im.load()
 
     def test_set_legacy_api(self):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
-        with self.assertRaises(Exception) as e:
+        with pytest.raises(Exception) as e:
             ifd.legacy_api = None
-        self.assertEqual(str(e.exception), "Not allowing setting of legacy api")
+        assert str(e.value) == "Not allowing setting of legacy api"
 
     def test_xyres_tiff(self):
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
 
             # legacy api
-            self.assertIsInstance(im.tag[X_RESOLUTION][0], tuple)
-            self.assertIsInstance(im.tag[Y_RESOLUTION][0], tuple)
+            assert isinstance(im.tag[X_RESOLUTION][0], tuple)
+            assert isinstance(im.tag[Y_RESOLUTION][0], tuple)
 
             # v2 api
-            self.assertIsInstance(im.tag_v2[X_RESOLUTION], TiffImagePlugin.IFDRational)
-            self.assertIsInstance(im.tag_v2[Y_RESOLUTION], TiffImagePlugin.IFDRational)
+            assert isinstance(im.tag_v2[X_RESOLUTION], TiffImagePlugin.IFDRational)
+            assert isinstance(im.tag_v2[Y_RESOLUTION], TiffImagePlugin.IFDRational)
 
-            self.assertEqual(im.info["dpi"], (72.0, 72.0))
+            assert im.info["dpi"] == (72.0, 72.0)
 
     def test_xyres_fallback_tiff(self):
         filename = "Tests/images/compression.tif"
         with Image.open(filename) as im:
 
             # v2 api
-            self.assertIsInstance(im.tag_v2[X_RESOLUTION], TiffImagePlugin.IFDRational)
-            self.assertIsInstance(im.tag_v2[Y_RESOLUTION], TiffImagePlugin.IFDRational)
-            self.assertRaises(KeyError, lambda: im.tag_v2[RESOLUTION_UNIT])
+            assert isinstance(im.tag_v2[X_RESOLUTION], TiffImagePlugin.IFDRational)
+            assert isinstance(im.tag_v2[Y_RESOLUTION], TiffImagePlugin.IFDRational)
+            with pytest.raises(KeyError):
+                im.tag_v2[RESOLUTION_UNIT]
 
             # Legacy.
-            self.assertEqual(im.info["resolution"], (100.0, 100.0))
+            assert im.info["resolution"] == (100.0, 100.0)
             # Fallback "inch".
-            self.assertEqual(im.info["dpi"], (100.0, 100.0))
+            assert im.info["dpi"] == (100.0, 100.0)
 
     def test_int_resolution(self):
         filename = "Tests/images/pil168.tif"
@@ -138,21 +139,21 @@ class TestFileTiff(PillowTestCase):
             im.tag_v2[X_RESOLUTION] = 71
             im.tag_v2[Y_RESOLUTION] = 71
             im._setup()
-            self.assertEqual(im.info["dpi"], (71.0, 71.0))
+            assert im.info["dpi"] == (71.0, 71.0)
 
     def test_load_dpi_rounding(self):
         for resolutionUnit, dpi in ((None, (72, 73)), (2, (72, 73)), (3, (183, 185))):
             with Image.open(
                 "Tests/images/hopper_roundDown_" + str(resolutionUnit) + ".tif"
             ) as im:
-                self.assertEqual(im.tag_v2.get(RESOLUTION_UNIT), resolutionUnit)
-                self.assertEqual(im.info["dpi"], (dpi[0], dpi[0]))
+                assert im.tag_v2.get(RESOLUTION_UNIT) == resolutionUnit
+                assert im.info["dpi"] == (dpi[0], dpi[0])
 
             with Image.open(
                 "Tests/images/hopper_roundUp_" + str(resolutionUnit) + ".tif"
             ) as im:
-                self.assertEqual(im.tag_v2.get(RESOLUTION_UNIT), resolutionUnit)
-                self.assertEqual(im.info["dpi"], (dpi[1], dpi[1]))
+                assert im.tag_v2.get(RESOLUTION_UNIT) == resolutionUnit
+                assert im.info["dpi"] == (dpi[1], dpi[1])
 
     def test_save_dpi_rounding(self):
         outfile = self.tempfile("temp.tif")
@@ -162,7 +163,7 @@ class TestFileTiff(PillowTestCase):
 
                 with Image.open(outfile) as reloaded:
                     reloaded.load()
-                    self.assertEqual((round(dpi), round(dpi)), reloaded.info["dpi"])
+                    assert (round(dpi), round(dpi)) == reloaded.info["dpi"]
 
     def test_save_setting_missing_resolution(self):
         b = BytesIO()
@@ -170,16 +171,18 @@ class TestFileTiff(PillowTestCase):
             b, format="tiff", resolution=123.45
         )
         with Image.open(b) as im:
-            self.assertEqual(float(im.tag_v2[X_RESOLUTION]), 123.45)
-            self.assertEqual(float(im.tag_v2[Y_RESOLUTION]), 123.45)
+            assert float(im.tag_v2[X_RESOLUTION]) == 123.45
+            assert float(im.tag_v2[Y_RESOLUTION]) == 123.45
 
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"
 
-        self.assertRaises(SyntaxError, TiffImagePlugin.TiffImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            TiffImagePlugin.TiffImageFile(invalid_file)
 
         TiffImagePlugin.PREFIXES.append(b"\xff\xd8\xff\xe0")
-        self.assertRaises(SyntaxError, TiffImagePlugin.TiffImageFile, invalid_file)
+        with pytest.raises(SyntaxError):
+            TiffImagePlugin.TiffImageFile(invalid_file)
         TiffImagePlugin.PREFIXES.pop()
 
     def test_bad_exif(self):
@@ -195,34 +198,35 @@ class TestFileTiff(PillowTestCase):
     def test_save_unsupported_mode(self):
         im = hopper("HSV")
         outfile = self.tempfile("temp.tif")
-        self.assertRaises(IOError, im.save, outfile)
+        with pytest.raises(IOError):
+            im.save(outfile)
 
     def test_little_endian(self):
         with Image.open("Tests/images/16bit.cropped.tif") as im:
-            self.assertEqual(im.getpixel((0, 0)), 480)
-            self.assertEqual(im.mode, "I;16")
+            assert im.getpixel((0, 0)) == 480
+            assert im.mode == "I;16"
 
             b = im.tobytes()
         # Bytes are in image native order (little endian)
-        self.assertEqual(b[0], ord(b"\xe0"))
-        self.assertEqual(b[1], ord(b"\x01"))
+        assert b[0] == ord(b"\xe0")
+        assert b[1] == ord(b"\x01")
 
     def test_big_endian(self):
         with Image.open("Tests/images/16bit.MM.cropped.tif") as im:
-            self.assertEqual(im.getpixel((0, 0)), 480)
-            self.assertEqual(im.mode, "I;16B")
+            assert im.getpixel((0, 0)) == 480
+            assert im.mode == "I;16B"
 
             b = im.tobytes()
         # Bytes are in image native order (big endian)
-        self.assertEqual(b[0], ord(b"\x01"))
-        self.assertEqual(b[1], ord(b"\xe0"))
+        assert b[0] == ord(b"\x01")
+        assert b[1] == ord(b"\xe0")
 
     def test_16bit_s(self):
         with Image.open("Tests/images/16bit.s.tif") as im:
             im.load()
-            self.assertEqual(im.mode, "I")
-            self.assertEqual(im.getpixel((0, 0)), 32767)
-            self.assertEqual(im.getpixel((0, 1)), 0)
+            assert im.mode == "I"
+            assert im.getpixel((0, 0)) == 32767
+            assert im.getpixel((0, 1)) == 0
 
     def test_12bit_rawmode(self):
         """ Are we generating the same interpretation
@@ -243,13 +247,12 @@ class TestFileTiff(PillowTestCase):
         with Image.open(path) as im:
             im.load()
 
-            self.assertEqual(im.getpixel((0, 0)), -0.4526388943195343)
-            self.assertEqual(im.getextrema(), (-3.140936851501465, 3.140684127807617))
+            assert im.getpixel((0, 0)) == -0.4526388943195343
+            assert im.getextrema() == (-3.140936851501465, 3.140684127807617)
 
     def test_unknown_pixel_mode(self):
-        self.assertRaises(
-            IOError, Image.open, "Tests/images/hopper_unknown_pixel_mode.tif"
-        )
+        with pytest.raises(IOError):
+            Image.open("Tests/images/hopper_unknown_pixel_mode.tif")
 
     def test_n_frames(self):
         for path, n_frames in [
@@ -257,16 +260,17 @@ class TestFileTiff(PillowTestCase):
             ["Tests/images/multipage.tiff", 3],
         ]:
             with Image.open(path) as im:
-                self.assertEqual(im.n_frames, n_frames)
-                self.assertEqual(im.is_animated, n_frames != 1)
+                assert im.n_frames == n_frames
+                assert im.is_animated == (n_frames != 1)
 
     def test_eoferror(self):
         with Image.open("Tests/images/multipage-lastframe.tif") as im:
             n_frames = im.n_frames
 
             # Test seeking past the last frame
-            self.assertRaises(EOFError, im.seek, n_frames)
-            self.assertLess(im.tell(), n_frames)
+            with pytest.raises(EOFError):
+                im.seek(n_frames)
+            assert im.tell() < n_frames
 
             # Test that seeking to the last frame does not raise an error
             im.seek(n_frames - 1)
@@ -277,29 +281,29 @@ class TestFileTiff(PillowTestCase):
             # file is a multipage tiff: 10x10 green, 10x10 red, 20x20 blue
 
             im.seek(0)
-            self.assertEqual(im.size, (10, 10))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 128, 0))
+            assert im.size == (10, 10)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 128, 0)
 
             im.seek(1)
             im.load()
-            self.assertEqual(im.size, (10, 10))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (255, 0, 0))
+            assert im.size == (10, 10)
+            assert im.convert("RGB").getpixel((0, 0)) == (255, 0, 0)
 
             im.seek(0)
             im.load()
-            self.assertEqual(im.size, (10, 10))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 128, 0))
+            assert im.size == (10, 10)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 128, 0)
 
             im.seek(2)
             im.load()
-            self.assertEqual(im.size, (20, 20))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 0, 255))
+            assert im.size == (20, 20)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 255)
 
     def test_multipage_last_frame(self):
         with Image.open("Tests/images/multipage-lastframe.tif") as im:
             im.load()
-            self.assertEqual(im.size, (20, 20))
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (0, 0, 255))
+            assert im.size == (20, 20)
+            assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 255)
 
     def test___str__(self):
         filename = "Tests/images/pil136.tiff"
@@ -309,7 +313,7 @@ class TestFileTiff(PillowTestCase):
             ret = str(im.ifd)
 
             # Assert
-            self.assertIsInstance(ret, str)
+            assert isinstance(ret, str)
 
     def test_dict(self):
         # Arrange
@@ -332,7 +336,7 @@ class TestFileTiff(PillowTestCase):
                 283: 72.0,
                 284: 1,
             }
-            self.assertEqual(dict(im.tag_v2), v2_tags)
+            assert dict(im.tag_v2) == v2_tags
 
             # legacy interface
             legacy_tags = {
@@ -350,7 +354,7 @@ class TestFileTiff(PillowTestCase):
                 283: ((720000, 10000),),
                 284: (1,),
             }
-            self.assertEqual(dict(im.tag), legacy_tags)
+            assert dict(im.tag) == legacy_tags
 
     def test__delitem__(self):
         filename = "Tests/images/pil136.tiff"
@@ -358,66 +362,68 @@ class TestFileTiff(PillowTestCase):
             len_before = len(dict(im.ifd))
             del im.ifd[256]
             len_after = len(dict(im.ifd))
-            self.assertEqual(len_before, len_after + 1)
+            assert len_before == len_after + 1
 
     def test_load_byte(self):
         for legacy_api in [False, True]:
             ifd = TiffImagePlugin.ImageFileDirectory_v2()
             data = b"abc"
             ret = ifd.load_byte(data, legacy_api)
-            self.assertEqual(ret, b"abc")
+            assert ret == b"abc"
 
     def test_load_string(self):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abc\0"
         ret = ifd.load_string(data, False)
-        self.assertEqual(ret, "abc")
+        assert ret == "abc"
 
     def test_load_float(self):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abcdabcd"
         ret = ifd.load_float(data, False)
-        self.assertEqual(ret, (1.6777999408082104e22, 1.6777999408082104e22))
+        assert ret == (1.6777999408082104e22, 1.6777999408082104e22)
 
     def test_load_double(self):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abcdefghabcdefgh"
         ret = ifd.load_double(data, False)
-        self.assertEqual(ret, (8.540883223036124e194, 8.540883223036124e194))
+        assert ret == (8.540883223036124e194, 8.540883223036124e194)
 
     def test_seek(self):
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
             im.seek(0)
-            self.assertEqual(im.tell(), 0)
+            assert im.tell() == 0
 
     def test_seek_eof(self):
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
-            self.assertEqual(im.tell(), 0)
-            self.assertRaises(EOFError, im.seek, -1)
-            self.assertRaises(EOFError, im.seek, 1)
+            assert im.tell() == 0
+            with pytest.raises(EOFError):
+                im.seek(-1)
+            with pytest.raises(EOFError):
+                im.seek(1)
 
     def test__limit_rational_int(self):
         from PIL.TiffImagePlugin import _limit_rational
 
         value = 34
         ret = _limit_rational(value, 65536)
-        self.assertEqual(ret, (34, 1))
+        assert ret == (34, 1)
 
     def test__limit_rational_float(self):
         from PIL.TiffImagePlugin import _limit_rational
 
         value = 22.3
         ret = _limit_rational(value, 65536)
-        self.assertEqual(ret, (223, 10))
+        assert ret == (223, 10)
 
     def test_4bit(self):
         test_file = "Tests/images/hopper_gray_4bpp.tif"
         original = hopper("L")
         with Image.open(test_file) as im:
-            self.assertEqual(im.size, (128, 128))
-            self.assertEqual(im.mode, "L")
+            assert im.size == (128, 128)
+            assert im.mode == "L"
             assert_image_similar(im, original, 7.3)
 
     def test_gray_semibyte_per_pixel(self):
@@ -444,13 +450,13 @@ class TestFileTiff(PillowTestCase):
         original = hopper("L")
         for epsilon, group in test_files:
             with Image.open(group[0]) as im:
-                self.assertEqual(im.size, (128, 128))
-                self.assertEqual(im.mode, "L")
+                assert im.size == (128, 128)
+                assert im.mode == "L"
                 assert_image_similar(im, original, epsilon)
                 for file in group[1:]:
                     with Image.open(file) as im2:
-                        self.assertEqual(im2.size, (128, 128))
-                        self.assertEqual(im2.mode, "L")
+                        assert im2.size == (128, 128)
+                        assert im2.mode == "L"
                         assert_image_equal(im, im2)
 
     def test_with_underscores(self):
@@ -460,19 +466,19 @@ class TestFileTiff(PillowTestCase):
         with Image.open(filename) as im:
 
             # legacy interface
-            self.assertEqual(im.tag[X_RESOLUTION][0][0], 72)
-            self.assertEqual(im.tag[Y_RESOLUTION][0][0], 36)
+            assert im.tag[X_RESOLUTION][0][0] == 72
+            assert im.tag[Y_RESOLUTION][0][0] == 36
 
             # v2 interface
-            self.assertEqual(im.tag_v2[X_RESOLUTION], 72)
-            self.assertEqual(im.tag_v2[Y_RESOLUTION], 36)
+            assert im.tag_v2[X_RESOLUTION] == 72
+            assert im.tag_v2[Y_RESOLUTION] == 36
 
     def test_roundtrip_tiff_uint16(self):
         # Test an image of all '0' values
         pixel_value = 0x1234
         infile = "Tests/images/uint16_1_4660.tif"
         with Image.open(infile) as im:
-            self.assertEqual(im.getpixel((0, 0)), pixel_value)
+            assert im.getpixel((0, 0)) == pixel_value
 
             tmpfile = self.tempfile("temp.tif")
             im.save(tmpfile)
@@ -523,7 +529,7 @@ class TestFileTiff(PillowTestCase):
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as im:
-            self.assertEqual(im.n_frames, 3)
+            assert im.n_frames == 3
 
         # Test appending images
         mp = BytesIO()
@@ -533,7 +539,7 @@ class TestFileTiff(PillowTestCase):
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as reread:
-            self.assertEqual(reread.n_frames, 3)
+            assert reread.n_frames == 3
 
         # Test appending using a generator
         def imGenerator(ims):
@@ -544,7 +550,7 @@ class TestFileTiff(PillowTestCase):
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as reread:
-            self.assertEqual(reread.n_frames, 3)
+            assert reread.n_frames == 3
 
     def test_saving_icc_profile(self):
         # Tests saving TIFF with icc_profile set.
@@ -558,7 +564,7 @@ class TestFileTiff(PillowTestCase):
         tmpfile = self.tempfile("temp.tif")
         im.save(tmpfile, "TIFF", compression="raw")
         with Image.open(tmpfile) as reloaded:
-            self.assertEqual(b"Dummy value", reloaded.info["icc_profile"])
+            assert b"Dummy value" == reloaded.info["icc_profile"]
 
     def test_close_on_load_exclusive(self):
         # similar to test_fd_leak, but runs on unixlike os
@@ -569,9 +575,9 @@ class TestFileTiff(PillowTestCase):
 
         im = Image.open(tmpfile)
         fp = im.fp
-        self.assertFalse(fp.closed)
+        assert not fp.closed
         im.load()
-        self.assertTrue(fp.closed)
+        assert fp.closed
 
     def test_close_on_load_nonexclusive(self):
         tmpfile = self.tempfile("temp.tif")
@@ -582,16 +588,16 @@ class TestFileTiff(PillowTestCase):
         with open(tmpfile, "rb") as f:
             im = Image.open(f)
             fp = im.fp
-            self.assertFalse(fp.closed)
+            assert not fp.closed
             im.load()
-            self.assertFalse(fp.closed)
+            assert not fp.closed
 
     # Ignore this UserWarning which triggers for four tags:
     # "Possibly corrupt EXIF data.  Expecting to read 50404352 bytes but..."
     @pytest.mark.filterwarnings("ignore:Possibly corrupt EXIF data")
     def test_string_dimension(self):
         # Assert that an error is raised if one of the dimensions is a string
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             Image.open("Tests/images/string_dimension.tiff")
 
 
@@ -606,10 +612,11 @@ class TestFileTiffW32(PillowTestCase):
 
         im = Image.open(tmpfile)
         fp = im.fp
-        self.assertFalse(fp.closed)
-        self.assertRaises(WindowsError, os.remove, tmpfile)
+        assert not fp.closed
+        with pytest.raises(WindowsError):
+            os.remove(tmpfile)
         im.load()
-        self.assertTrue(fp.closed)
+        assert fp.closed
 
         # this closes the mmap
         im.close()

Tests/test_file_tiff_metadata.py

@@ -55,14 +55,14 @@ class TestFileTiffMetadata(PillowTestCase):
 
         with Image.open(f) as loaded:
 
-            self.assertEqual(loaded.tag[ImageJMetaDataByteCounts], (len(bindata),))
-            self.assertEqual(loaded.tag_v2[ImageJMetaDataByteCounts], (len(bindata),))
+            assert loaded.tag[ImageJMetaDataByteCounts] == (len(bindata),)
+            assert loaded.tag_v2[ImageJMetaDataByteCounts] == (len(bindata),)
 
-            self.assertEqual(loaded.tag[ImageJMetaData], bindata)
-            self.assertEqual(loaded.tag_v2[ImageJMetaData], bindata)
+            assert loaded.tag[ImageJMetaData] == bindata
+            assert loaded.tag_v2[ImageJMetaData] == bindata
 
-            self.assertEqual(loaded.tag[ImageDescription], (reloaded_textdata,))
-            self.assertEqual(loaded.tag_v2[ImageDescription], reloaded_textdata)
+            assert loaded.tag[ImageDescription] == (reloaded_textdata,)
+            assert loaded.tag_v2[ImageDescription] == reloaded_textdata
 
             loaded_float = loaded.tag[tag_ids["RollAngle"]][0]
             self.assertAlmostEqual(loaded_float, floatdata, places=5)
@@ -75,59 +75,49 @@ class TestFileTiffMetadata(PillowTestCase):
         img.save(f, tiffinfo=info)
         with Image.open(f) as loaded:
 
-            self.assertEqual(
-                loaded.tag[ImageJMetaDataByteCounts], (8, len(bindata) - 8)
-            )
-            self.assertEqual(
-                loaded.tag_v2[ImageJMetaDataByteCounts], (8, len(bindata) - 8)
-            )
+            assert loaded.tag[ImageJMetaDataByteCounts] == (8, len(bindata) - 8)
+            assert loaded.tag_v2[ImageJMetaDataByteCounts] == (8, len(bindata) - 8)
 
     def test_read_metadata(self):
         with Image.open("Tests/images/hopper_g4.tif") as img:
 
-            self.assertEqual(
-                {
-                    "YResolution": IFDRational(4294967295, 113653537),
-                    "PlanarConfiguration": 1,
-                    "BitsPerSample": (1,),
-                    "ImageLength": 128,
-                    "Compression": 4,
-                    "FillOrder": 1,
-                    "RowsPerStrip": 128,
-                    "ResolutionUnit": 3,
-                    "PhotometricInterpretation": 0,
-                    "PageNumber": (0, 1),
-                    "XResolution": IFDRational(4294967295, 113653537),
-                    "ImageWidth": 128,
-                    "Orientation": 1,
-                    "StripByteCounts": (1968,),
-                    "SamplesPerPixel": 1,
-                    "StripOffsets": (8,),
-                },
-                img.tag_v2.named(),
-            )
+            assert {
+                "YResolution": IFDRational(4294967295, 113653537),
+                "PlanarConfiguration": 1,
+                "BitsPerSample": (1,),
+                "ImageLength": 128,
+                "Compression": 4,
+                "FillOrder": 1,
+                "RowsPerStrip": 128,
+                "ResolutionUnit": 3,
+                "PhotometricInterpretation": 0,
+                "PageNumber": (0, 1),
+                "XResolution": IFDRational(4294967295, 113653537),
+                "ImageWidth": 128,
+                "Orientation": 1,
+                "StripByteCounts": (1968,),
+                "SamplesPerPixel": 1,
+                "StripOffsets": (8,),
+            } == img.tag_v2.named()
 
-            self.assertEqual(
-                {
-                    "YResolution": ((4294967295, 113653537),),
-                    "PlanarConfiguration": (1,),
-                    "BitsPerSample": (1,),
-                    "ImageLength": (128,),
-                    "Compression": (4,),
-                    "FillOrder": (1,),
-                    "RowsPerStrip": (128,),
-                    "ResolutionUnit": (3,),
-                    "PhotometricInterpretation": (0,),
-                    "PageNumber": (0, 1),
-                    "XResolution": ((4294967295, 113653537),),
-                    "ImageWidth": (128,),
-                    "Orientation": (1,),
-                    "StripByteCounts": (1968,),
-                    "SamplesPerPixel": (1,),
-                    "StripOffsets": (8,),
-                },
-                img.tag.named(),
-            )
+            assert {
+                "YResolution": ((4294967295, 113653537),),
+                "PlanarConfiguration": (1,),
+                "BitsPerSample": (1,),
+                "ImageLength": (128,),
+                "Compression": (4,),
+                "FillOrder": (1,),
+                "RowsPerStrip": (128,),
+                "ResolutionUnit": (3,),
+                "PhotometricInterpretation": (0,),
+                "PageNumber": (0, 1),
+                "XResolution": ((4294967295, 113653537),),
+                "ImageWidth": (128,),
+                "Orientation": (1,),
+                "StripByteCounts": (1968,),
+                "SamplesPerPixel": (1,),
+                "StripOffsets": (8,),
+            } == img.tag.named()
 
     def test_write_metadata(self):
         """ Test metadata writing through the python code """
@@ -156,19 +146,17 @@ class TestFileTiffMetadata(PillowTestCase):
                     "{} didn't roundtrip, {}, {}".format(tag, original[tag], value),
                 )
             else:
-                self.assertEqual(
-                    original[tag],
-                    value,
-                    "{} didn't roundtrip, {}, {}".format(tag, original[tag], value),
+                assert original[tag] == value, "{} didn't roundtrip, {}, {}".format(
+                    tag, original[tag], value
                 )
 
         for tag, value in original.items():
             if tag not in ignored:
-                self.assertEqual(value, reloaded[tag], "%s didn't roundtrip" % tag)
+                assert value == reloaded[tag], "%s didn't roundtrip" % tag
 
     def test_no_duplicate_50741_tag(self):
-        self.assertEqual(tag_ids["MakerNoteSafety"], 50741)
-        self.assertEqual(tag_ids["BestQualityScale"], 50780)
+        assert tag_ids["MakerNoteSafety"] == 50741
+        assert tag_ids["BestQualityScale"] == 50780
 
     def test_empty_metadata(self):
         f = io.BytesIO(b"II*\x00\x08\x00\x00\x00")
@@ -184,8 +172,8 @@ class TestFileTiffMetadata(PillowTestCase):
             im.save(out)
 
         with Image.open(out) as reloaded:
-            self.assertNotIsInstance(im.info["icc_profile"], tuple)
-            self.assertEqual(im.info["icc_profile"], reloaded.info["icc_profile"])
+            assert not isinstance(im.info["icc_profile"], tuple)
+            assert im.info["icc_profile"] == reloaded.info["icc_profile"]
 
     def test_iccprofile_binary(self):
         # https://github.com/python-pillow/Pillow/issues/1526
@@ -193,8 +181,8 @@ class TestFileTiffMetadata(PillowTestCase):
         # but probably won't be able to save it.
 
         with Image.open("Tests/images/hopper.iccprofile_binary.tif") as im:
-            self.assertEqual(im.tag_v2.tagtype[34675], 1)
-            self.assertTrue(im.info["icc_profile"])
+            assert im.tag_v2.tagtype[34675] == 1
+            assert im.info["icc_profile"]
 
     def test_iccprofile_save_png(self):
         with Image.open("Tests/images/hopper.iccprofile.tif") as im:
@@ -215,8 +203,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(0, reloaded.tag_v2[41988].numerator)
-            self.assertEqual(0, reloaded.tag_v2[41988].denominator)
+            assert 0 == reloaded.tag_v2[41988].numerator
+            assert 0 == reloaded.tag_v2[41988].denominator
 
     def test_ifd_unsigned_rational(self):
         im = hopper()
@@ -233,8 +221,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(max_long, reloaded.tag_v2[41493].numerator)
-            self.assertEqual(1, reloaded.tag_v2[41493].denominator)
+            assert max_long == reloaded.tag_v2[41493].numerator
+            assert 1 == reloaded.tag_v2[41493].denominator
 
         # out of bounds of 4 byte unsigned long
         numerator = max_long + 1
@@ -245,8 +233,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(max_long, reloaded.tag_v2[41493].numerator)
-            self.assertEqual(1, reloaded.tag_v2[41493].denominator)
+            assert max_long == reloaded.tag_v2[41493].numerator
+            assert 1 == reloaded.tag_v2[41493].denominator
 
     def test_ifd_signed_rational(self):
         im = hopper()
@@ -262,8 +250,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(numerator, reloaded.tag_v2[37380].numerator)
-            self.assertEqual(denominator, reloaded.tag_v2[37380].denominator)
+            assert numerator == reloaded.tag_v2[37380].numerator
+            assert denominator == reloaded.tag_v2[37380].denominator
 
         numerator = -(2 ** 31)
         denominator = 2 ** 31 - 1
@@ -274,8 +262,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(numerator, reloaded.tag_v2[37380].numerator)
-            self.assertEqual(denominator, reloaded.tag_v2[37380].denominator)
+            assert numerator == reloaded.tag_v2[37380].numerator
+            assert denominator == reloaded.tag_v2[37380].denominator
 
         # out of bounds of 4 byte signed long
         numerator = -(2 ** 31) - 1
@@ -287,8 +275,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(2 ** 31 - 1, reloaded.tag_v2[37380].numerator)
-            self.assertEqual(-1, reloaded.tag_v2[37380].denominator)
+            assert 2 ** 31 - 1 == reloaded.tag_v2[37380].numerator
+            assert -1 == reloaded.tag_v2[37380].denominator
 
     def test_ifd_signed_long(self):
         im = hopper()
@@ -300,7 +288,7 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression="raw")
 
         with Image.open(out) as reloaded:
-            self.assertEqual(reloaded.tag_v2[37000], -60000)
+            assert reloaded.tag_v2[37000] == -60000
 
     def test_empty_values(self):
         data = io.BytesIO(
@@ -314,17 +302,17 @@ class TestFileTiffMetadata(PillowTestCase):
         info.load(data)
         # Should not raise ValueError.
         info = dict(info)
-        self.assertIn(33432, info)
+        assert 33432 in info
 
     def test_PhotoshopInfo(self):
         with Image.open("Tests/images/issue_2278.tif") as im:
-            self.assertEqual(len(im.tag_v2[34377]), 1)
-            self.assertIsInstance(im.tag_v2[34377][0], bytes)
+            assert len(im.tag_v2[34377]) == 1
+            assert isinstance(im.tag_v2[34377][0], bytes)
             out = self.tempfile("temp.tiff")
             im.save(out)
         with Image.open(out) as reloaded:
-            self.assertEqual(len(reloaded.tag_v2[34377]), 1)
-            self.assertIsInstance(reloaded.tag_v2[34377][0], bytes)
+            assert len(reloaded.tag_v2[34377]) == 1
+            assert isinstance(reloaded.tag_v2[34377][0], bytes)
 
     def test_too_many_entries(self):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()

Tests/test_file_webp.py

@@ -47,9 +47,9 @@ class TestFileWebp(PillowTestCase):
         """
 
         with Image.open("Tests/images/hopper.webp") as image:
-            self.assertEqual(image.mode, self.rgb_mode)
-            self.assertEqual(image.size, (128, 128))
-            self.assertEqual(image.format, "WEBP")
+            assert image.mode == self.rgb_mode
+            assert image.size == (128, 128)
+            assert image.format == "WEBP"
             image.load()
             image.getdata()
 
@@ -67,9 +67,9 @@ class TestFileWebp(PillowTestCase):
 
         hopper(self.rgb_mode).save(temp_file)
         with Image.open(temp_file) as image:
-            self.assertEqual(image.mode, self.rgb_mode)
-            self.assertEqual(image.size, (128, 128))
-            self.assertEqual(image.format, "WEBP")
+            assert image.mode == self.rgb_mode
+            assert image.size == (128, 128)
+            assert image.format == "WEBP"
             image.load()
             image.getdata()
 
@@ -95,9 +95,9 @@ class TestFileWebp(PillowTestCase):
         temp_file = self.tempfile("temp.webp")
         hopper("L").save(temp_file)
         with Image.open(temp_file) as image:
-            self.assertEqual(image.mode, self.rgb_mode)
-            self.assertEqual(image.size, (128, 128))
-            self.assertEqual(image.format, "WEBP")
+            assert image.mode == self.rgb_mode
+            assert image.size == (128, 128)
+            assert image.format == "WEBP"
 
             image.load()
             image.getdata()
@@ -114,9 +114,9 @@ class TestFileWebp(PillowTestCase):
         temp_file = self.tempfile("temp.webp")
         hopper("P").save(temp_file)
         with Image.open(temp_file) as image:
-            self.assertEqual(image.mode, self.rgb_mode)
-            self.assertEqual(image.size, (128, 128))
-            self.assertEqual(image.format, "WEBP")
+            assert image.mode == self.rgb_mode
+            assert image.size == (128, 128)
+            assert image.format == "WEBP"
 
             image.load()
             image.getdata()
@@ -130,8 +130,10 @@ class TestFileWebp(PillowTestCase):
         """
 
         if _webp.HAVE_WEBPANIM:
-            self.assertRaises(TypeError, _webp.WebPAnimEncoder)
-        self.assertRaises(TypeError, _webp.WebPEncode)
+            with pytest.raises(TypeError):
+                _webp.WebPAnimEncoder()
+        with pytest.raises(TypeError):
+            _webp.WebPEncode()
 
     def test_WebPDecode_with_invalid_args(self):
         """
@@ -139,8 +141,10 @@ class TestFileWebp(PillowTestCase):
         """
 
         if _webp.HAVE_WEBPANIM:
-            self.assertRaises(TypeError, _webp.WebPAnimDecoder)
-        self.assertRaises(TypeError, _webp.WebPDecode)
+            with pytest.raises(TypeError):
+                _webp.WebPAnimDecoder()
+        with pytest.raises(TypeError):
+            _webp.WebPDecode()
 
     def test_no_resource_warning(self):
         file_path = "Tests/images/hopper.webp"
@@ -173,4 +177,4 @@ class TestFileWebp(PillowTestCase):
         difference = sum(
             [abs(original_value[i] - reread_value[i]) for i in range(0, 3)]
         )
-        self.assertLess(difference, 5)
+        assert difference < 5

Tests/test_file_wmf.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, WmfImagePlugin
 
 from .helper import PillowTestCase, assert_image_similar, hopper
@@ -39,7 +40,7 @@ class TestFileWmf(PillowTestCase):
         im = hopper()
         tmpfile = self.tempfile("temp.wmf")
         im.save(tmpfile)
-        self.assertTrue(handler.methodCalled)
+        assert handler.methodCalled
 
         # Restore the state before this test
         WmfImagePlugin.register_handler(None)
@@ -47,19 +48,19 @@ class TestFileWmf(PillowTestCase):
     def test_load_dpi_rounding(self):
         # Round up
         with Image.open("Tests/images/drawing.emf") as im:
-            self.assertEqual(im.info["dpi"], 1424)
+            assert im.info["dpi"] == 1424
 
         # Round down
         with Image.open("Tests/images/drawing_roundDown.emf") as im:
-            self.assertEqual(im.info["dpi"], 1426)
+            assert im.info["dpi"] == 1426
 
     def test_load_set_dpi(self):
         with Image.open("Tests/images/drawing.wmf") as im:
-            self.assertEqual(im.size, (82, 82))
+            assert im.size == (82, 82)
 
             if hasattr(Image.core, "drawwmf"):
                 im.load(144)
-                self.assertEqual(im.size, (164, 164))
+                assert im.size == (164, 164)
 
                 with Image.open("Tests/images/drawing_wmf_ref_144.png") as expected:
                     assert_image_similar(im, expected, 2.0)
@@ -69,4 +70,5 @@ class TestFileWmf(PillowTestCase):
 
         for ext in [".wmf", ".emf"]:
             tmpfile = self.tempfile("temp" + ext)
-            self.assertRaises(IOError, im.save, tmpfile)
+            with pytest.raises(IOError):
+                im.save(tmpfile)

Tests/test_font_pcf.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import FontFile, Image, ImageDraw, ImageFont, PcfFontFile
 
 from .helper import (
@@ -17,9 +18,9 @@ class TestFontPcf(PillowTestCase):
     def save_font(self):
         with open(fontname, "rb") as test_file:
             font = PcfFontFile.PcfFontFile(test_file)
-        self.assertIsInstance(font, FontFile.FontFile)
+        assert isinstance(font, FontFile.FontFile)
         # check the number of characters in the font
-        self.assertEqual(len([_f for _f in font.glyph if _f]), 223)
+        assert len([_f for _f in font.glyph if _f]) == 223
 
         tempname = self.tempfile("temp.pil")
         self.addCleanup(self.delete_tempfile, tempname[:-4] + ".pbm")
@@ -31,7 +32,7 @@ class TestFontPcf(PillowTestCase):
 
         with open(tempname, "rb") as f_loaded:
             with open("Tests/fonts/10x20.pil", "rb") as f_target:
-                self.assertEqual(f_loaded.read(), f_target.read())
+                assert f_loaded.read() == f_target.read()
         return tempname
 
     def test_sanity(self):
@@ -39,7 +40,8 @@ class TestFontPcf(PillowTestCase):
 
     def test_invalid_file(self):
         with open("Tests/images/flower.jpg", "rb") as fp:
-            self.assertRaises(SyntaxError, PcfFontFile.PcfFontFile, fp)
+            with pytest.raises(SyntaxError):
+                PcfFontFile.PcfFontFile(fp)
 
     def test_draw(self):
         tempname = self.save_font()
@@ -55,11 +57,11 @@ class TestFontPcf(PillowTestCase):
         font = ImageFont.load(tempname)
         for i in range(255):
             (dx, dy) = font.getsize(chr(i))
-            self.assertEqual(dy, 20)
-            self.assertIn(dx, (0, 10))
+            assert dy == 20
+            assert dx in (0, 10)
         for l in range(len(message)):
             msg = message[: l + 1]
-            self.assertEqual(font.getsize(msg), (len(msg) * 10, 20))
+            assert font.getsize(msg) == (len(msg) * 10, 20)
 
     def _test_high_characters(self, message):
         tempname = self.save_font()

Tests/test_image.py

@@ -53,66 +53,72 @@ class TestImage(PillowTestCase):
             "BGR;24",
             "BGR;32",
         ]:
-            with self.assertRaises(ValueError) as e:
+            with pytest.raises(ValueError) as e:
                 Image.new(mode, (1, 1))
-            self.assertEqual(str(e.exception), "unrecognized image mode")
+            assert str(e.value) == "unrecognized image mode"
 
     def test_exception_inheritance(self):
-        self.assertTrue(issubclass(UnidentifiedImageError, IOError))
+        assert issubclass(UnidentifiedImageError, IOError)
 
     def test_sanity(self):
 
         im = Image.new("L", (100, 100))
-        self.assertEqual(repr(im)[:45], "<PIL.Image.Image image mode=L size=100x100 at")
-        self.assertEqual(im.mode, "L")
-        self.assertEqual(im.size, (100, 100))
+        assert repr(im)[:45] == "<PIL.Image.Image image mode=L size=100x100 at"
+        assert im.mode == "L"
+        assert im.size == (100, 100)
 
         im = Image.new("RGB", (100, 100))
-        self.assertEqual(repr(im)[:45], "<PIL.Image.Image image mode=RGB size=100x100 ")
-        self.assertEqual(im.mode, "RGB")
-        self.assertEqual(im.size, (100, 100))
+        assert repr(im)[:45] == "<PIL.Image.Image image mode=RGB size=100x100 "
+        assert im.mode == "RGB"
+        assert im.size == (100, 100)
 
         Image.new("L", (100, 100), None)
         im2 = Image.new("L", (100, 100), 0)
         im3 = Image.new("L", (100, 100), "black")
 
-        self.assertEqual(im2.getcolors(), [(10000, 0)])
-        self.assertEqual(im3.getcolors(), [(10000, 0)])
+        assert im2.getcolors() == [(10000, 0)]
+        assert im3.getcolors() == [(10000, 0)]
 
-        self.assertRaises(ValueError, Image.new, "X", (100, 100))
-        self.assertRaises(ValueError, Image.new, "", (100, 100))
-        # self.assertRaises(MemoryError, Image.new, "L", (1000000, 1000000))
+        with pytest.raises(ValueError):
+            Image.new("X", (100, 100))
+        with pytest.raises(ValueError):
+            Image.new("", (100, 100))
+        # with pytest.raises(MemoryError):
+        #   Image.new("L", (1000000, 1000000))
 
     def test_width_height(self):
         im = Image.new("RGB", (1, 2))
-        self.assertEqual(im.width, 1)
-        self.assertEqual(im.height, 2)
+        assert im.width == 1
+        assert im.height == 2
 
-        with self.assertRaises(AttributeError):
+        with pytest.raises(AttributeError):
             im.size = (3, 4)
 
     def test_invalid_image(self):
         import io
 
         im = io.BytesIO(b"")
-        self.assertRaises(UnidentifiedImageError, Image.open, im)
+        with pytest.raises(UnidentifiedImageError):
+            Image.open(im)
 
     def test_bad_mode(self):
-        self.assertRaises(ValueError, Image.open, "filename", "bad mode")
+        with pytest.raises(ValueError):
+            Image.open("filename", "bad mode")
 
     def test_stringio(self):
-        self.assertRaises(ValueError, Image.open, io.StringIO())
+        with pytest.raises(ValueError):
+            Image.open(io.StringIO())
 
     def test_pathlib(self):
         from PIL.Image import Path
 
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
-            self.assertEqual(im.mode, "P")
-            self.assertEqual(im.size, (10, 10))
+            assert im.mode == "P"
+            assert im.size == (10, 10)
 
         with Image.open(Path("Tests/images/hopper.jpg")) as im:
-            self.assertEqual(im.mode, "RGB")
-            self.assertEqual(im.size, (128, 128))
+            assert im.mode == "RGB"
+            assert im.size == (128, 128)
 
             temp_file = self.tempfile("temp.jpg")
             if os.path.exists(temp_file):
@@ -145,17 +151,18 @@ class TestImage(PillowTestCase):
     def test_unknown_extension(self):
         im = hopper()
         temp_file = self.tempfile("temp.unknown")
-        self.assertRaises(ValueError, im.save, temp_file)
+        with pytest.raises(ValueError):
+            im.save(temp_file)
 
     def test_internals(self):
         im = Image.new("L", (100, 100))
         im.readonly = 1
         im._copy()
-        self.assertFalse(im.readonly)
+        assert not im.readonly
 
         im.readonly = 1
         im.paste(0, (0, 0, 100, 100))
-        self.assertFalse(im.readonly)
+        assert not im.readonly
 
     @unittest.skipIf(is_win32(), "Test requires opening tempfile twice")
     def test_readonly_save(self):
@@ -163,7 +170,7 @@ class TestImage(PillowTestCase):
         shutil.copy("Tests/images/rgb32bf-rgba.bmp", temp_file)
 
         with Image.open(temp_file) as im:
-            self.assertTrue(im.readonly)
+            assert im.readonly
             im.save(temp_file)
 
     def test_dump(self):
@@ -174,7 +181,8 @@ class TestImage(PillowTestCase):
         im._dump(self.tempfile("temp_RGB.ppm"))
 
         im = Image.new("HSV", (10, 10))
-        self.assertRaises(ValueError, im._dump, self.tempfile("temp_HSV.ppm"))
+        with pytest.raises(ValueError):
+            im._dump(self.tempfile("temp_HSV.ppm"))
 
     def test_comparison_with_other_type(self):
         # Arrange
@@ -183,8 +191,8 @@ class TestImage(PillowTestCase):
 
         # Act/Assert
         # Shouldn't cause AttributeError (#774)
-        self.assertFalse(item is None)
-        self.assertFalse(item == num)
+        assert item is not None
+        assert item != num
 
     def test_expand_x(self):
         # Arrange
@@ -196,8 +204,8 @@ class TestImage(PillowTestCase):
         im = im._expand(xmargin)
 
         # Assert
-        self.assertEqual(im.size[0], orig_size[0] + 2 * xmargin)
-        self.assertEqual(im.size[1], orig_size[1] + 2 * xmargin)
+        assert im.size[0] == orig_size[0] + 2 * xmargin
+        assert im.size[1] == orig_size[1] + 2 * xmargin
 
     def test_expand_xy(self):
         # Arrange
@@ -210,21 +218,25 @@ class TestImage(PillowTestCase):
         im = im._expand(xmargin, ymargin)
 
         # Assert
-        self.assertEqual(im.size[0], orig_size[0] + 2 * xmargin)
-        self.assertEqual(im.size[1], orig_size[1] + 2 * ymargin)
+        assert im.size[0] == orig_size[0] + 2 * xmargin
+        assert im.size[1] == orig_size[1] + 2 * ymargin
 
     def test_getbands(self):
         # Assert
-        self.assertEqual(hopper("RGB").getbands(), ("R", "G", "B"))
-        self.assertEqual(hopper("YCbCr").getbands(), ("Y", "Cb", "Cr"))
+        assert hopper("RGB").getbands() == ("R", "G", "B")
+        assert hopper("YCbCr").getbands() == ("Y", "Cb", "Cr")
 
     def test_getchannel_wrong_params(self):
         im = hopper()
 
-        self.assertRaises(ValueError, im.getchannel, -1)
-        self.assertRaises(ValueError, im.getchannel, 3)
-        self.assertRaises(ValueError, im.getchannel, "Z")
-        self.assertRaises(ValueError, im.getchannel, "1")
+        with pytest.raises(ValueError):
+            im.getchannel(-1)
+        with pytest.raises(ValueError):
+            im.getchannel(3)
+        with pytest.raises(ValueError):
+            im.getchannel("Z")
+        with pytest.raises(ValueError):
+            im.getchannel("1")
 
     def test_getchannel(self):
         im = hopper("YCbCr")
@@ -245,7 +257,7 @@ class TestImage(PillowTestCase):
         bbox = im.getbbox()
 
         # Assert
-        self.assertEqual(bbox, (0, 0, 128, 128))
+        assert bbox == (0, 0, 128, 128)
 
     def test_ne(self):
         # Arrange
@@ -253,7 +265,7 @@ class TestImage(PillowTestCase):
         im2 = Image.new("RGB", (25, 25), "white")
 
         # Act / Assert
-        self.assertNotEqual(im1, im2)
+        assert im1 != im2
 
     def test_alpha_composite(self):
         # https://stackoverflow.com/questions/3374878
@@ -284,7 +296,7 @@ class TestImage(PillowTestCase):
 
         # Assert
         img_colors = sorted(img.getcolors())
-        self.assertEqual(img_colors, expected_colors)
+        assert img_colors == expected_colors
 
     def test_alpha_inplace(self):
         src = Image.new("RGBA", (128, 128), "blue")
@@ -304,31 +316,35 @@ class TestImage(PillowTestCase):
         offset = src.copy()
         offset.alpha_composite(over, (64, 64))
         assert_image_equal(offset.crop((64, 64, 127, 127)), target.crop((0, 0, 63, 63)))
-        self.assertEqual(offset.size, (128, 128))
+        assert offset.size == (128, 128)
 
         # offset and crop
         box = src.copy()
         box.alpha_composite(over, (64, 64), (0, 0, 32, 32))
         assert_image_equal(box.crop((64, 64, 96, 96)), target.crop((0, 0, 32, 32)))
         assert_image_equal(box.crop((96, 96, 128, 128)), src.crop((0, 0, 32, 32)))
-        self.assertEqual(box.size, (128, 128))
+        assert box.size == (128, 128)
 
         # source point
         source = src.copy()
         source.alpha_composite(over, (32, 32), (32, 32, 96, 96))
 
         assert_image_equal(source.crop((32, 32, 96, 96)), target.crop((32, 32, 96, 96)))
-        self.assertEqual(source.size, (128, 128))
+        assert source.size == (128, 128)
 
         # errors
-        self.assertRaises(ValueError, source.alpha_composite, over, "invalid source")
-        self.assertRaises(
-            ValueError, source.alpha_composite, over, (0, 0), "invalid destination"
-        )
-        self.assertRaises(ValueError, source.alpha_composite, over, 0)
-        self.assertRaises(ValueError, source.alpha_composite, over, (0, 0), 0)
-        self.assertRaises(ValueError, source.alpha_composite, over, (0, -1))
-        self.assertRaises(ValueError, source.alpha_composite, over, (0, 0), (0, -1))
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, "invalid source")
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, (0, 0), "invalid destination")
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, 0)
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, (0, 0), 0)
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, (0, -1))
+        with pytest.raises(ValueError):
+            source.alpha_composite(over, (0, 0), (0, -1))
 
     def test_registered_extensions_uninitialized(self):
         # Arrange
@@ -340,11 +356,11 @@ class TestImage(PillowTestCase):
         Image.registered_extensions()
 
         # Assert
-        self.assertEqual(Image._initialized, 2)
+        assert Image._initialized == 2
 
         # Restore the original state and assert
         Image.EXTENSION = extension
-        self.assertTrue(Image.EXTENSION)
+        assert Image.EXTENSION
 
     def test_registered_extensions(self):
         # Arrange
@@ -356,9 +372,9 @@ class TestImage(PillowTestCase):
         extensions = Image.registered_extensions()
 
         # Assert
-        self.assertTrue(extensions)
+        assert extensions
         for ext in [".cur", ".icns", ".tif", ".tiff"]:
-            self.assertIn(ext, extensions)
+            assert ext in extensions
 
     def test_effect_mandelbrot(self):
         # Arrange
@@ -370,7 +386,7 @@ class TestImage(PillowTestCase):
         im = Image.effect_mandelbrot(size, extent, quality)
 
         # Assert
-        self.assertEqual(im.size, (512, 512))
+        assert im.size == (512, 512)
         with Image.open("Tests/images/effect_mandelbrot.png") as im2:
             assert_image_equal(im, im2)
 
@@ -383,7 +399,8 @@ class TestImage(PillowTestCase):
         quality = 1
 
         # Act/Assert
-        self.assertRaises(ValueError, Image.effect_mandelbrot, size, extent, quality)
+        with pytest.raises(ValueError):
+            Image.effect_mandelbrot(size, extent, quality)
 
     def test_effect_noise(self):
         # Arrange
@@ -394,8 +411,8 @@ class TestImage(PillowTestCase):
         im = Image.effect_noise(size, sigma)
 
         # Assert
-        self.assertEqual(im.size, (100, 100))
-        self.assertEqual(im.mode, "L")
+        assert im.size == (100, 100)
+        assert im.mode == "L"
         p0 = im.getpixel((0, 0))
         p1 = im.getpixel((0, 1))
         p2 = im.getpixel((0, 2))
@@ -412,34 +429,34 @@ class TestImage(PillowTestCase):
         im2 = im.effect_spread(distance)
 
         # Assert
-        self.assertEqual(im.size, (128, 128))
+        assert im.size == (128, 128)
         with Image.open("Tests/images/effect_spread.png") as im3:
             assert_image_similar(im2, im3, 110)
 
     def test_check_size(self):
         # Checking that the _check_size function throws value errors
         # when we want it to.
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             Image.new("RGB", 0)  # not a tuple
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             Image.new("RGB", (0,))  # Tuple too short
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             Image.new("RGB", (-1, -1))  # w,h < 0
 
         # this should pass with 0 sized images, #2259
         im = Image.new("L", (0, 0))
-        self.assertEqual(im.size, (0, 0))
+        assert im.size == (0, 0)
 
         im = Image.new("L", (0, 100))
-        self.assertEqual(im.size, (0, 100))
+        assert im.size == (0, 100)
 
         im = Image.new("L", (100, 0))
-        self.assertEqual(im.size, (100, 0))
+        assert im.size == (100, 0)
 
-        self.assertTrue(Image.new("RGB", (1, 1)))
+        assert Image.new("RGB", (1, 1))
         # Should pass lists too
         i = Image.new("RGB", [1, 1])
-        self.assertIsInstance(i.size, tuple)
+        assert isinstance(i.size, tuple)
 
     def test_storage_neg(self):
         # Storage.c accepted negative values for xsize, ysize.  Was
@@ -447,7 +464,7 @@ class TestImage(PillowTestCase):
         # removed Calling directly into core to test the error in
         # Storage.c, rather than the size check above
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             Image.core.fill("RGB", (2, -2), (0, 0, 0))
 
     def test_offset_not_implemented(self):
@@ -455,17 +472,20 @@ class TestImage(PillowTestCase):
         with hopper() as im:
 
             # Act / Assert
-            self.assertRaises(NotImplementedError, im.offset, None)
+            with pytest.raises(NotImplementedError):
+                im.offset(None)
 
     def test_fromstring(self):
-        self.assertRaises(NotImplementedError, Image.fromstring)
+        with pytest.raises(NotImplementedError):
+            Image.fromstring()
 
     def test_linear_gradient_wrong_mode(self):
         # Arrange
         wrong_mode = "RGB"
 
         # Act / Assert
-        self.assertRaises(ValueError, Image.linear_gradient, wrong_mode)
+        with pytest.raises(ValueError):
+            Image.linear_gradient(wrong_mode)
 
     def test_linear_gradient(self):
 
@@ -477,10 +497,10 @@ class TestImage(PillowTestCase):
             im = Image.linear_gradient(mode)
 
             # Assert
-            self.assertEqual(im.size, (256, 256))
-            self.assertEqual(im.mode, mode)
-            self.assertEqual(im.getpixel((0, 0)), 0)
-            self.assertEqual(im.getpixel((255, 255)), 255)
+            assert im.size == (256, 256)
+            assert im.mode == mode
+            assert im.getpixel((0, 0)) == 0
+            assert im.getpixel((255, 255)) == 255
             with Image.open(target_file) as target:
                 target = target.convert(mode)
             assert_image_equal(im, target)
@@ -490,7 +510,8 @@ class TestImage(PillowTestCase):
         wrong_mode = "RGB"
 
         # Act / Assert
-        self.assertRaises(ValueError, Image.radial_gradient, wrong_mode)
+        with pytest.raises(ValueError):
+            Image.radial_gradient(wrong_mode)
 
     def test_radial_gradient(self):
 
@@ -502,10 +523,10 @@ class TestImage(PillowTestCase):
             im = Image.radial_gradient(mode)
 
             # Assert
-            self.assertEqual(im.size, (256, 256))
-            self.assertEqual(im.mode, mode)
-            self.assertEqual(im.getpixel((0, 0)), 255)
-            self.assertEqual(im.getpixel((128, 128)), 0)
+            assert im.size == (256, 256)
+            assert im.mode == mode
+            assert im.getpixel((0, 0)) == 255
+            assert im.getpixel((128, 128)) == 0
             with Image.open(target_file) as target:
                 target = target.convert(mode)
             assert_image_equal(im, target)
@@ -524,12 +545,13 @@ class TestImage(PillowTestCase):
         for ext in exts:
             del Image.EXTENSION[ext]
 
-        self.assertEqual(ext_individual, ext_multiple)
+        assert ext_individual == ext_multiple
 
     def test_remap_palette(self):
         # Test illegal image mode
         with hopper() as im:
-            self.assertRaises(ValueError, im.remap_palette, None)
+            with pytest.raises(ValueError):
+                im.remap_palette(None)
 
     def test__new(self):
         im = hopper("RGB")
@@ -542,13 +564,13 @@ class TestImage(PillowTestCase):
 
         def _make_new(base_image, im, palette_result=None):
             new_im = base_image._new(im)
-            self.assertEqual(new_im.mode, im.mode)
-            self.assertEqual(new_im.size, im.size)
-            self.assertEqual(new_im.info, base_image.info)
+            assert new_im.mode == im.mode
+            assert new_im.size == im.size
+            assert new_im.info == base_image.info
             if palette_result is not None:
-                self.assertEqual(new_im.palette.tobytes(), palette_result.tobytes())
+                assert new_im.palette.tobytes() == palette_result.tobytes()
             else:
-                self.assertIsNone(new_im.palette)
+                assert new_im.palette is None
 
         _make_new(im, im_p, im_p.palette)
         _make_new(im_p, im, None)
@@ -587,7 +609,7 @@ class TestImage(PillowTestCase):
             with Image.open(fp) as im:
                 im.load()
 
-            self.assertFalse(fp.closed)
+            assert not fp.closed
 
     def test_overrun(self):
         for file in [
@@ -603,14 +625,14 @@ class TestImage(PillowTestCase):
                     im.load()
                     self.assertFail()
                 except OSError as e:
-                    self.assertEqual(str(e), "buffer overrun when reading image file")
+                    assert str(e) == "buffer overrun when reading image file"
 
         with Image.open("Tests/images/fli_overrun2.bin") as im:
             try:
                 im.seek(1)
                 self.assertFail()
             except OSError as e:
-                self.assertEqual(str(e), "buffer overrun when reading image file")
+                assert str(e) == "buffer overrun when reading image file"
 
 
 class MockEncoder:
@@ -627,19 +649,13 @@ class TestRegistry(PillowTestCase):
     def test_encode_registry(self):
 
         Image.register_encoder("MOCK", mock_encode)
-        self.assertIn("MOCK", Image.ENCODERS)
+        assert "MOCK" in Image.ENCODERS
 
         enc = Image._getencoder("RGB", "MOCK", ("args",), extra=("extra",))
 
-        self.assertIsInstance(enc, MockEncoder)
-        self.assertEqual(enc.args, ("RGB", "args", "extra"))
+        assert isinstance(enc, MockEncoder)
+        assert enc.args == ("RGB", "args", "extra")
 
     def test_encode_registry_fail(self):
-        self.assertRaises(
-            IOError,
-            Image._getencoder,
-            "RGB",
-            "DoesNotExist",
-            ("args",),
-            extra=("extra",),
-        )
+        with pytest.raises(IOError):
+            Image._getencoder("RGB", "DoesNotExist", ("args",), extra=("extra",))

Tests/test_image_access.py

@@ -5,6 +5,7 @@ import sys
 import unittest
 from distutils import ccompiler, sysconfig
 
+import pytest
 from PIL import Image
 
 from .helper import PillowTestCase, assert_image_equal, hopper, is_win32, on_ci
@@ -55,7 +56,7 @@ class TestImagePutPixel(AccessTest):
                 pos = x, y
                 im2.putpixel(pos, im1.getpixel(pos))
 
-        self.assertFalse(im2.readonly)
+        assert not im2.readonly
         assert_image_equal(im1, im2)
 
         im2 = Image.new(im1.mode, im1.size, 0)
@@ -74,8 +75,8 @@ class TestImagePutPixel(AccessTest):
         im2 = Image.new(im1.mode, im1.size, 0)
 
         width, height = im1.size
-        self.assertEqual(im1.getpixel((0, 0)), im1.getpixel((-width, -height)))
-        self.assertEqual(im1.getpixel((-1, -1)), im1.getpixel((width - 1, height - 1)))
+        assert im1.getpixel((0, 0)) == im1.getpixel((-width, -height))
+        assert im1.getpixel((-1, -1)) == im1.getpixel((width - 1, height - 1))
 
         for y in range(-1, -im1.size[1] - 1, -1):
             for x in range(-1, -im1.size[0] - 1, -1):
@@ -92,7 +93,7 @@ class TestImagePutPixel(AccessTest):
                 pos = x, y
                 im2.putpixel(pos, im1.getpixel(pos))
 
-        self.assertFalse(im2.readonly)
+        assert not im2.readonly
         assert_image_equal(im1, im2)
 
         im2 = Image.new(im1.mode, im1.size, 0)
@@ -123,54 +124,45 @@ class TestImageGetPixel(AccessTest):
         # check putpixel
         im = Image.new(mode, (1, 1), None)
         im.putpixel((0, 0), c)
-        self.assertEqual(
-            im.getpixel((0, 0)),
-            c,
-            "put/getpixel roundtrip failed for mode {}, color {}".format(mode, c),
-        )
+        assert (
+            im.getpixel((0, 0)) == c
+        ), "put/getpixel roundtrip failed for mode {}, color {}".format(mode, c)
 
         # check putpixel negative index
         im.putpixel((-1, -1), c)
-        self.assertEqual(
-            im.getpixel((-1, -1)),
-            c,
-            "put/getpixel roundtrip negative index failed"
-            " for mode %s, color %s" % (mode, c),
+        assert im.getpixel((-1, -1)) == c, (
+            "put/getpixel roundtrip negative index failed for mode %s, color %s"
+            % (mode, c)
         )
 
         # Check 0
         im = Image.new(mode, (0, 0), None)
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.putpixel((0, 0), c)
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.getpixel((0, 0))
         # Check 0 negative index
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.putpixel((-1, -1), c)
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.getpixel((-1, -1))
 
         # check initial color
         im = Image.new(mode, (1, 1), c)
-        self.assertEqual(
-            im.getpixel((0, 0)),
-            c,
-            "initial color failed for mode {}, color {} ".format(mode, c),
-        )
+        assert (
+            im.getpixel((0, 0)) == c
+        ), "initial color failed for mode {}, color {} ".format(mode, c)
         # check initial color negative index
-        self.assertEqual(
-            im.getpixel((-1, -1)),
-            c,
-            "initial color failed with negative index"
-            "for mode %s, color %s " % (mode, c),
-        )
+        assert (
+            im.getpixel((-1, -1)) == c
+        ), "initial color failed with negative index for mode %s, color %s " % (mode, c)
 
         # Check 0
         im = Image.new(mode, (0, 0), c)
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.getpixel((0, 0))
         # Check 0 negative index
-        with self.assertRaises(IndexError):
+        with pytest.raises(IndexError):
             im.getpixel((-1, -1))
 
     def test_basic(self):
@@ -205,7 +197,7 @@ class TestImageGetPixel(AccessTest):
         for color in [(255, 0, 0), (255, 0, 0, 255)]:
             im = Image.new("P", (1, 1), 0)
             im.putpixel((0, 0), color)
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (255, 0, 0))
+            assert im.convert("RGB").getpixel((0, 0)) == (255, 0, 0)
 
 
 @unittest.skipIf(cffi is None, "No cffi")
@@ -233,7 +225,7 @@ class TestCffi(AccessTest):
         w, h = im.size
         for x in range(0, w, 10):
             for y in range(0, h, 10):
-                self.assertEqual(access[(x, y)], caccess[(x, y)])
+                assert access[(x, y)] == caccess[(x, y)]
 
         # Access an out-of-range pixel
         self.assertRaises(
@@ -280,11 +272,11 @@ class TestCffi(AccessTest):
         for x in range(0, w, 10):
             for y in range(0, h, 10):
                 access[(x, y)] = color
-                self.assertEqual(color, caccess[(x, y)])
+                assert color == caccess[(x, y)]
 
         # Attempt to set the value on a read-only image
         access = PyAccess.new(im, True)
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             access[(0, 0)] = color
 
     def test_set_vs_c(self):
@@ -314,7 +306,7 @@ class TestCffi(AccessTest):
         # self._test_set_access(im, 2**13-1)
 
     def test_not_implemented(self):
-        self.assertIsNone(PyAccess.new(hopper("BGR;15")))
+        assert PyAccess.new(hopper("BGR;15")) is None
 
     # ref https://github.com/python-pillow/Pillow/pull/2009
     def test_reference_counting(self):
@@ -325,14 +317,14 @@ class TestCffi(AccessTest):
             px = Image.new("L", (size, 1), 0).load()
             for i in range(size):
                 # pixels can contain garbage if image is released
-                self.assertEqual(px[i, 0], 0)
+                assert px[i, 0] == 0
 
     def test_p_putpixel_rgb_rgba(self):
         for color in [(255, 0, 0), (255, 0, 0, 255)]:
             im = Image.new("P", (1, 1), 0)
             access = PyAccess.new(im, False)
             access.putpixel((0, 0), color)
-            self.assertEqual(im.convert("RGB").getpixel((0, 0)), (255, 0, 0))
+            assert im.convert("RGB").getpixel((0, 0)) == (255, 0, 0)
 
 
 class TestEmbeddable(unittest.TestCase):
@@ -387,4 +379,4 @@ int main(int argc, char* argv[])
 
         process = subprocess.Popen(["embed_pil.exe"], env=env)
         process.communicate()
-        self.assertEqual(process.returncode, 0)
+        assert process.returncode == 0

Tests/test_image_convert.py

@@ -14,8 +14,8 @@ class TestImageConvert(PillowTestCase):
     def test_sanity(self):
         def convert(im, mode):
             out = im.convert(mode)
-            self.assertEqual(out.mode, mode)
-            self.assertEqual(out.size, im.size)
+            assert out.mode == mode
+            assert out.size == im.size
 
         modes = (
             "1",
@@ -57,7 +57,7 @@ class TestImageConvert(PillowTestCase):
     def _test_float_conversion(self, im):
         orig = im.getpixel((5, 5))
         converted = im.convert("F").getpixel((5, 5))
-        self.assertEqual(orig, converted)
+        assert orig == converted
 
     def test_8bit(self):
         with Image.open("Tests/images/hopper.jpg") as im:
@@ -87,11 +87,11 @@ class TestImageConvert(PillowTestCase):
         f = self.tempfile("temp.png")
 
         im_l = im.convert("L")
-        self.assertEqual(im_l.info["transparency"], 0)  # undone
+        assert im_l.info["transparency"] == 0  # undone
         im_l.save(f)
 
         im_rgb = im.convert("RGB")
-        self.assertEqual(im_rgb.info["transparency"], (0, 0, 0))  # undone
+        assert im_rgb.info["transparency"] == (0, 0, 0)  # undone
         im_rgb.save(f)
 
     # ref https://github.com/python-pillow/Pillow/issues/664
@@ -105,9 +105,9 @@ class TestImageConvert(PillowTestCase):
         im_rgba = im.convert("RGBA")
 
         # Assert
-        self.assertNotIn("transparency", im_rgba.info)
+        assert "transparency" not in im_rgba.info
         # https://github.com/python-pillow/Pillow/issues/2702
-        self.assertIsNone(im_rgba.palette)
+        assert im_rgba.palette is None
 
     def test_trns_l(self):
         im = hopper("L")
@@ -116,15 +116,15 @@ class TestImageConvert(PillowTestCase):
         f = self.tempfile("temp.png")
 
         im_rgb = im.convert("RGB")
-        self.assertEqual(im_rgb.info["transparency"], (128, 128, 128))  # undone
+        assert im_rgb.info["transparency"] == (128, 128, 128)  # undone
         im_rgb.save(f)
 
         im_p = im.convert("P")
-        self.assertIn("transparency", im_p.info)
+        assert "transparency" in im_p.info
         im_p.save(f)
 
         im_p = pytest.warns(UserWarning, im.convert, "P", palette=Image.ADAPTIVE)
-        self.assertNotIn("transparency", im_p.info)
+        assert "transparency" not in im_p.info
         im_p.save(f)
 
     def test_trns_RGB(self):
@@ -134,19 +134,19 @@ class TestImageConvert(PillowTestCase):
         f = self.tempfile("temp.png")
 
         im_l = im.convert("L")
-        self.assertEqual(im_l.info["transparency"], im_l.getpixel((0, 0)))  # undone
+        assert im_l.info["transparency"] == im_l.getpixel((0, 0))  # undone
         im_l.save(f)
 
         im_p = im.convert("P")
-        self.assertIn("transparency", im_p.info)
+        assert "transparency" in im_p.info
         im_p.save(f)
 
         im_rgba = im.convert("RGBA")
-        self.assertNotIn("transparency", im_rgba.info)
+        assert "transparency" not in im_rgba.info
         im_rgba.save(f)
 
         im_p = pytest.warns(UserWarning, im.convert, "P", palette=Image.ADAPTIVE)
-        self.assertNotIn("transparency", im_p.info)
+        assert "transparency" not in im_p.info
         im_p.save(f)
 
     def test_gif_with_rgba_palette_to_p(self):
@@ -154,7 +154,7 @@ class TestImageConvert(PillowTestCase):
         with Image.open("Tests/images/hopper.gif") as im:
             im.info["transparency"] = 255
             im.load()
-            self.assertEqual(im.palette.mode, "RGBA")
+            assert im.palette.mode == "RGBA"
             im_p = im.convert("P")
 
         # Should not raise ValueError: unrecognized raw mode
@@ -178,10 +178,11 @@ class TestImageConvert(PillowTestCase):
             0.212671, 0.715160, 0.072169, 0,
             0.019334, 0.119193, 0.950227, 0)
         # fmt: on
-        self.assertNotEqual(im.mode, "RGB")
+        assert im.mode != "RGB"
 
         # Act / Assert
-        self.assertRaises(ValueError, im.convert, mode="CMYK", matrix=matrix)
+        with pytest.raises(ValueError):
+            im.convert(mode="CMYK", matrix=matrix)
 
     def test_matrix_wrong_mode(self):
         # Arrange
@@ -192,10 +193,11 @@ class TestImageConvert(PillowTestCase):
             0.212671, 0.715160, 0.072169, 0,
             0.019334, 0.119193, 0.950227, 0)
         # fmt: on
-        self.assertEqual(im.mode, "L")
+        assert im.mode == "L"
 
         # Act / Assert
-        self.assertRaises(ValueError, im.convert, mode="L", matrix=matrix)
+        with pytest.raises(ValueError):
+            im.convert(mode="L", matrix=matrix)
 
     def test_matrix_xyz(self):
         def matrix_convert(mode):
@@ -208,22 +210,22 @@ class TestImageConvert(PillowTestCase):
                 0.212671, 0.715160, 0.072169, 0,
                 0.019334, 0.119193, 0.950227, 0)
             # fmt: on
-            self.assertEqual(im.mode, "RGB")
+            assert im.mode == "RGB"
 
             # Act
             # Convert an RGB image to the CIE XYZ colour space
             converted_im = im.convert(mode=mode, matrix=matrix)
 
             # Assert
-            self.assertEqual(converted_im.mode, mode)
-            self.assertEqual(converted_im.size, im.size)
+            assert converted_im.mode == mode
+            assert converted_im.size == im.size
             with Image.open("Tests/images/hopper-XYZ.png") as target:
                 if converted_im.mode == "RGB":
                     assert_image_similar(converted_im, target, 3)
-                    self.assertEqual(converted_im.info["transparency"], (105, 54, 4))
+                    assert converted_im.info["transparency"] == (105, 54, 4)
                 else:
                     assert_image_similar(converted_im, target.getchannel(0), 1)
-                    self.assertEqual(converted_im.info["transparency"], 105)
+                    assert converted_im.info["transparency"] == 105
 
         matrix_convert("RGB")
         matrix_convert("L")
@@ -237,7 +239,7 @@ class TestImageConvert(PillowTestCase):
             0, 1, 0, 0,
             0, 0, 1, 0)
         # fmt: on
-        self.assertEqual(im.mode, "RGB")
+        assert im.mode == "RGB"
 
         # Act
         # Convert with an identity matrix

Tests/test_image_paste.py

@@ -23,7 +23,7 @@ class TestImagingPaste(PillowTestCase):
             px[self.size // 2, self.size - 1],
             px[self.size - 1, self.size - 1],
         ]
-        self.assertEqual(actual, expected)
+        assert actual == expected
 
     def assert_9points_paste(self, im, im2, mask, expected):
         im3 = im.copy()
@@ -199,8 +199,8 @@ class TestImagingPaste(PillowTestCase):
             hist = im.crop(rect).histogram()
             while hist:
                 head, hist = hist[:256], hist[256:]
-                self.assertEqual(head[255], 128 * 128)
-                self.assertEqual(sum(head[:255]), 0)
+                assert head[255] == 128 * 128
+                assert sum(head[:255]) == 0
 
     def test_color_mask_1(self):
         for mode in ("RGBA", "RGB", "L"):

Tests/test_image_reduce.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, ImageMath, ImageMode
 
 from .helper import PillowTestCase, convert_to_comparable
@@ -39,51 +40,51 @@ class TestImageReduce(PillowTestCase):
     def test_args_factor(self):
         im = Image.new("L", (10, 10))
 
-        self.assertEqual((4, 4), im.reduce(3).size)
-        self.assertEqual((4, 10), im.reduce((3, 1)).size)
-        self.assertEqual((10, 4), im.reduce((1, 3)).size)
+        assert (4, 4) == im.reduce(3).size
+        assert (4, 10) == im.reduce((3, 1)).size
+        assert (10, 4) == im.reduce((1, 3)).size
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(0)
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             im.reduce(2.0)
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce((0, 10))
 
     def test_args_box(self):
         im = Image.new("L", (10, 10))
 
-        self.assertEqual((5, 5), im.reduce(2, (0, 0, 10, 10)).size)
-        self.assertEqual((1, 1), im.reduce(2, (5, 5, 6, 6)).size)
+        assert (5, 5) == im.reduce(2, (0, 0, 10, 10)).size
+        assert (1, 1) == im.reduce(2, (5, 5, 6, 6)).size
 
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             im.reduce(2, "stri")
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             im.reduce(2, 2)
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (0, 0, 11, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (0, 0, 10, 11))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (-1, 0, 10, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (0, -1, 10, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (0, 5, 10, 5))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(2, (5, 0, 5, 10))
 
     def test_unsupported_modes(self):
         im = Image.new("P", (10, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(3)
 
         im = Image.new("1", (10, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(3)
 
         im = Image.new("I;16", (10, 10))
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.reduce(3)
 
     def get_image(self, mode):
@@ -109,7 +110,7 @@ class TestImageReduce(PillowTestCase):
         box = (11, 13, 146, 164)
         reduced = im.reduce(factor, box=box)
         reference = im.crop(box).reduce(factor)
-        self.assertEqual(reduced, reference)
+        assert reduced == reference
 
     def compare_reduce_with_reference(self, im, factor, average_diff=0.4, max_diff=1):
         """Image.reduce() should look very similar to Image.resize(BOX).
@@ -135,13 +136,13 @@ class TestImageReduce(PillowTestCase):
         reference.paste(area, (0, 0))
 
         if area_size[0] < reduced.size[0]:
-            self.assertEqual(reduced.size[0] - area_size[0], 1)
+            assert reduced.size[0] - area_size[0] == 1
             last_column_box = (area_box[2], 0, im.size[0], area_box[3])
             last_column = im.resize((1, area_size[1]), Image.BOX, last_column_box)
             reference.paste(last_column, (area_size[0], 0))
 
         if area_size[1] < reduced.size[1]:
-            self.assertEqual(reduced.size[1] - area_size[1], 1)
+            assert reduced.size[1] - area_size[1] == 1
             last_row_box = (0, area_box[3], area_box[2], im.size[1])
             last_row = im.resize((area_size[0], 1), Image.BOX, last_row_box)
             reference.paste(last_row, (0, area_size[1]))
@@ -154,8 +155,8 @@ class TestImageReduce(PillowTestCase):
         self.assert_compare_images(reduced, reference, average_diff, max_diff)
 
     def assert_compare_images(self, a, b, max_average_diff, max_diff=255):
-        self.assertEqual(a.mode, b.mode, "got mode %r, expected %r" % (a.mode, b.mode))
-        self.assertEqual(a.size, b.size, "got size %r, expected %r" % (a.size, b.size))
+        assert a.mode == b.mode, "got mode %r, expected %r" % (a.mode, b.mode)
+        assert a.size == b.size, "got size %r, expected %r" % (a.size, b.size)
 
         a, b = convert_to_comparable(a, b)
 
@@ -167,22 +168,15 @@ class TestImageReduce(PillowTestCase):
             average_diff = sum(i * num for i, num in enumerate(ch_hist)) / (
                 a.size[0] * a.size[1]
             )
-            self.assertGreaterEqual(
-                max_average_diff,
-                average_diff,
-                (
-                    "average pixel value difference {:.4f} > expected {:.4f} "
-                    "for '{}' band"
-                ).format(average_diff, max_average_diff, band),
-            )
+            msg = "average pixel value difference {:.4f} > expected {:.4f} "
+            "for '{}' band".format(average_diff, max_average_diff, band)
+            assert max_average_diff >= average_diff, msg
 
             last_diff = [i for i, num in enumerate(ch_hist) if num > 0][-1]
-            self.assertGreaterEqual(
-                max_diff,
-                last_diff,
-                "max pixel value difference {} > expected {} for '{}' band".format(
-                    last_diff, max_diff, band
-                ),
+            assert (
+                max_diff >= last_diff
+            ), "max pixel value difference {} > expected {} for '{}' band".format(
+                last_diff, max_diff, band
             )
 
     def test_mode_L(self):

Tests/test_image_resample.py

@@ -1,6 +1,7 @@
 import unittest
 from contextlib import contextmanager
 
+import pytest
 from PIL import Image, ImageDraw
 
 from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
@@ -16,7 +17,7 @@ class TestImagingResampleVulnerability(PillowTestCase):
             (size_too_large, size_normal),
             (size_normal, size_too_large),
         ):
-            with self.assertRaises(MemoryError):
+            with pytest.raises(MemoryError):
                 # any resampling filter will do here
                 im.im.resize((xsize, ysize), Image.BILINEAR)
 
@@ -26,10 +27,10 @@ class TestImagingResampleVulnerability(PillowTestCase):
         # Should not crash
         im.resize((100, 100))
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.resize((-100, 100))
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             im.resize((100, -100))
 
     def test_modify_after_resizing(self):
@@ -39,7 +40,7 @@ class TestImagingResampleVulnerability(PillowTestCase):
         # some in-place operation
         copy.paste("black", (0, 0, im.width // 2, im.height // 2))
         # image should be different
-        self.assertNotEqual(im.tobytes(), copy.tobytes())
+        assert im.tobytes() != copy.tobytes()
 
 
 class TestImagingCoreResampleAccuracy(PillowTestCase):
@@ -84,7 +85,7 @@ class TestImagingCoreResampleAccuracy(PillowTestCase):
                     message = "\nHave: \n{}\n\nExpected: \n{}".format(
                         self.serialize_image(case), self.serialize_image(sample)
                     )
-                    self.assertEqual(s_px[x, y], c_px[x, y], message)
+                    assert s_px[x, y] == c_px[x, y], message
 
     def serialize_image(self, image):
         s_px = image.load()
@@ -230,7 +231,7 @@ class CoreResampleConsistencyTest(PillowTestCase):
             for y in range(channel.size[1]):
                 if px[x, y] != color:
                     message = "{} != {} for pixel {}".format(px[x, y], color, (x, y))
-                    self.assertEqual(px[x, y], color, message)
+                    assert px[x, y] == color, message
 
     def test_8u(self):
         im, color = self.make_case("RGB", (0, 64, 255))
@@ -268,11 +269,10 @@ class CoreResampleAlphaCorrectTest(PillowTestCase):
         px = i.load()
         for y in range(i.size[1]):
             used_colors = {px[x, y][0] for x in range(i.size[0])}
-            self.assertEqual(
-                256,
-                len(used_colors),
-                "All colors should present in resized image. "
-                "Only {} on {} line.".format(len(used_colors), y),
+            assert 256 == len(
+                used_colors
+            ), "All colors should present in resized image. Only {} on {} line.".format(
+                len(used_colors), y
             )
 
     @unittest.skip("current implementation isn't precise enough")
@@ -311,7 +311,7 @@ class CoreResampleAlphaCorrectTest(PillowTestCase):
                     message = "pixel at ({}, {}) is differ:\n{}\n{}".format(
                         x, y, px[x, y], clean_pixel
                     )
-                    self.assertEqual(px[x, y][:3], clean_pixel, message)
+                    assert px[x, y][:3] == clean_pixel, message
 
     def test_dirty_pixels_rgba(self):
         case = self.make_dirty_case("RGBA", (255, 255, 0, 128), (0, 0, 255, 0))
@@ -335,7 +335,7 @@ class CoreResamplePassesTest(PillowTestCase):
     def count(self, diff):
         count = Image.core.get_stats()["new_count"]
         yield
-        self.assertEqual(Image.core.get_stats()["new_count"] - count, diff)
+        assert Image.core.get_stats()["new_count"] - count == diff
 
     def test_horizontal(self):
         im = hopper("L")
@@ -384,7 +384,7 @@ class CoreResampleCoefficientsTest(PillowTestCase):
 
             px = i.resize((5, i.size[1]), Image.BICUBIC).load()
             if px[2, 0] != test_color // 2:
-                self.assertEqual(test_color // 2, px[2, 0])
+                assert test_color // 2 == px[2, 0]
 
     def test_nonzero_coefficients(self):
         # regression test for the wrong coefficients calculation
@@ -393,13 +393,13 @@ class CoreResampleCoefficientsTest(PillowTestCase):
         histogram = im.resize((256, 256), Image.BICUBIC).histogram()
 
         # first channel
-        self.assertEqual(histogram[0x100 * 0 + 0x20], 0x10000)
+        assert histogram[0x100 * 0 + 0x20] == 0x10000
         # second channel
-        self.assertEqual(histogram[0x100 * 1 + 0x40], 0x10000)
+        assert histogram[0x100 * 1 + 0x40] == 0x10000
         # third channel
-        self.assertEqual(histogram[0x100 * 2 + 0x60], 0x10000)
+        assert histogram[0x100 * 2 + 0x60] == 0x10000
         # fourth channel
-        self.assertEqual(histogram[0x100 * 3 + 0xFF], 0x10000)
+        assert histogram[0x100 * 3 + 0xFF] == 0x10000
 
 
 class CoreResampleBoxTest(PillowTestCase):
@@ -456,7 +456,7 @@ class CoreResampleBoxTest(PillowTestCase):
 
     def test_tiles(self):
         with Image.open("Tests/images/flower.jpg") as im:
-            self.assertEqual(im.size, (480, 360))
+            assert im.size == (480, 360)
             dst_size = (251, 188)
             reference = im.resize(dst_size, Image.BICUBIC)
 
@@ -468,7 +468,7 @@ class CoreResampleBoxTest(PillowTestCase):
         # This test shows advantages of the subpixel resizing
         # after supersampling (e.g. during JPEG decoding).
         with Image.open("Tests/images/flower.jpg") as im:
-            self.assertEqual(im.size, (480, 360))
+            assert im.size == (480, 360)
             dst_size = (48, 36)
             # Reference is cropped image resized to destination
             reference = im.crop((0, 0, 473, 353)).resize(dst_size, Image.BICUBIC)
@@ -503,7 +503,7 @@ class CoreResampleBoxTest(PillowTestCase):
             ((40, 50), (10, 20, 50, 70)),
         ]:
             res = im.resize(size, Image.LANCZOS, box)
-            self.assertEqual(res.size, size)
+            assert res.size == size
             assert_image_equal(res, im.crop(box), ">>> {} {}".format(size, box))
 
     def test_no_passthrough(self):
@@ -517,7 +517,7 @@ class CoreResampleBoxTest(PillowTestCase):
             ((40, 50), (10.4, 20.4, 50.4, 70.4)),
         ]:
             res = im.resize(size, Image.LANCZOS, box)
-            self.assertEqual(res.size, size)
+            assert res.size == size
             with self.assertRaisesRegex(AssertionError, r"difference \d"):
                 # check that the difference at least that much
                 assert_image_similar(
@@ -536,7 +536,7 @@ class CoreResampleBoxTest(PillowTestCase):
                 ((40, 50), (10, 20, 50, 90)),
             ]:
                 res = im.resize(size, flt, box)
-                self.assertEqual(res.size, size)
+                assert res.size == size
                 # Borders should be slightly different
                 assert_image_similar(
                     res,
@@ -557,7 +557,7 @@ class CoreResampleBoxTest(PillowTestCase):
                 ((40, 50), (20, 10, 90, 60)),
             ]:
                 res = im.resize(size, flt, box)
-                self.assertEqual(res.size, size)
+                assert res.size == size
                 # Borders should be slightly different
                 assert_image_similar(
                     res,

Tests/test_image_resize.py

@@ -3,6 +3,7 @@ Tests for resize functionality.
 """
 from itertools import permutations
 
+import pytest
 from PIL import Image
 
 from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
@@ -29,26 +30,23 @@ class TestImagingCoreResize(PillowTestCase):
         ]:  # exotic mode
             im = hopper(mode)
             r = self.resize(im, (15, 12), Image.NEAREST)
-            self.assertEqual(r.mode, mode)
-            self.assertEqual(r.size, (15, 12))
-            self.assertEqual(r.im.bands, im.im.bands)
+            assert r.mode == mode
+            assert r.size == (15, 12)
+            assert r.im.bands == im.im.bands
 
     def test_convolution_modes(self):
-        self.assertRaises(
-            ValueError, self.resize, hopper("1"), (15, 12), Image.BILINEAR
-        )
-        self.assertRaises(
-            ValueError, self.resize, hopper("P"), (15, 12), Image.BILINEAR
-        )
-        self.assertRaises(
-            ValueError, self.resize, hopper("I;16"), (15, 12), Image.BILINEAR
-        )
+        with pytest.raises(ValueError):
+            self.resize(hopper("1"), (15, 12), Image.BILINEAR)
+        with pytest.raises(ValueError):
+            self.resize(hopper("P"), (15, 12), Image.BILINEAR)
+        with pytest.raises(ValueError):
+            self.resize(hopper("I;16"), (15, 12), Image.BILINEAR)
         for mode in ["L", "I", "F", "RGB", "RGBA", "CMYK", "YCbCr"]:
             im = hopper(mode)
             r = self.resize(im, (15, 12), Image.BILINEAR)
-            self.assertEqual(r.mode, mode)
-            self.assertEqual(r.size, (15, 12))
-            self.assertEqual(r.im.bands, im.im.bands)
+            assert r.mode == mode
+            assert r.size == (15, 12)
+            assert r.im.bands == im.im.bands
 
     def test_reduce_filters(self):
         for f in [
@@ -60,8 +58,8 @@ class TestImagingCoreResize(PillowTestCase):
             Image.LANCZOS,
         ]:
             r = self.resize(hopper("RGB"), (15, 12), f)
-            self.assertEqual(r.mode, "RGB")
-            self.assertEqual(r.size, (15, 12))
+            assert r.mode == "RGB"
+            assert r.size == (15, 12)
 
     def test_enlarge_filters(self):
         for f in [
@@ -73,8 +71,8 @@ class TestImagingCoreResize(PillowTestCase):
             Image.LANCZOS,
         ]:
             r = self.resize(hopper("RGB"), (212, 195), f)
-            self.assertEqual(r.mode, "RGB")
-            self.assertEqual(r.size, (212, 195))
+            assert r.mode == "RGB"
+            assert r.size == (212, 195)
 
     def test_endianness(self):
         # Make an image with one colored pixel, in one channel.
@@ -128,12 +126,13 @@ class TestImagingCoreResize(PillowTestCase):
             Image.LANCZOS,
         ]:
             r = self.resize(Image.new("RGB", (0, 0), "white"), (212, 195), f)
-            self.assertEqual(r.mode, "RGB")
-            self.assertEqual(r.size, (212, 195))
-            self.assertEqual(r.getdata()[0], (0, 0, 0))
+            assert r.mode == "RGB"
+            assert r.size == (212, 195)
+            assert r.getdata()[0] == (0, 0, 0)
 
     def test_unknown_filter(self):
-        self.assertRaises(ValueError, self.resize, hopper(), (10, 10), 9)
+        with pytest.raises(ValueError):
+            self.resize(hopper(), (10, 10), 9)
 
 
 class TestReducingGapResize(PillowTestCase):
@@ -147,10 +146,10 @@ class TestReducingGapResize(PillowTestCase):
         im = self.gradients_image.resize((52, 34), Image.BICUBIC)
         assert_image_equal(ref, im)
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             self.gradients_image.resize((52, 34), Image.BICUBIC, reducing_gap=0)
 
-        with self.assertRaises(ValueError):
+        with pytest.raises(ValueError):
             self.gradients_image.resize((52, 34), Image.BICUBIC, reducing_gap=0.99)
 
     def test_reducing_gap_1(self):
@@ -164,7 +163,7 @@ class TestReducingGapResize(PillowTestCase):
                 (52, 34), Image.BICUBIC, box=box, reducing_gap=1.0
             )
 
-            with self.assertRaises(AssertionError):
+            with pytest.raises(AssertionError):
                 assert_image_equal(ref, im)
 
             assert_image_similar(ref, im, epsilon)
@@ -180,7 +179,7 @@ class TestReducingGapResize(PillowTestCase):
                 (52, 34), Image.BICUBIC, box=box, reducing_gap=2.0
             )
 
-            with self.assertRaises(AssertionError):
+            with pytest.raises(AssertionError):
                 assert_image_equal(ref, im)
 
             assert_image_similar(ref, im, epsilon)
@@ -196,7 +195,7 @@ class TestReducingGapResize(PillowTestCase):
                 (52, 34), Image.BICUBIC, box=box, reducing_gap=3.0
             )
 
-            with self.assertRaises(AssertionError):
+            with pytest.raises(AssertionError):
                 assert_image_equal(ref, im)
 
             assert_image_similar(ref, im, epsilon)
@@ -227,8 +226,8 @@ class TestImageResize(PillowTestCase):
     def test_resize(self):
         def resize(mode, size):
             out = hopper(mode).resize(size)
-            self.assertEqual(out.mode, mode)
-            self.assertEqual(out.size, size)
+            assert out.mode == mode
+            assert out.size == size
 
         for mode in "1", "P", "L", "RGB", "I", "F":
             resize(mode, (112, 103))
@@ -236,13 +235,14 @@ class TestImageResize(PillowTestCase):
 
         # Test unknown resampling filter
         with hopper() as im:
-            self.assertRaises(ValueError, im.resize, (10, 10), "unknown")
+            with pytest.raises(ValueError):
+                im.resize((10, 10), "unknown")
 
     def test_default_filter(self):
         for mode in "L", "RGB", "I", "F":
             im = hopper(mode)
-            self.assertEqual(im.resize((20, 20), Image.BICUBIC), im.resize((20, 20)))
+            assert im.resize((20, 20), Image.BICUBIC) == im.resize((20, 20))
 
         for mode in "1", "P":
             im = hopper(mode)
-            self.assertEqual(im.resize((20, 20), Image.NEAREST), im.resize((20, 20)))
+            assert im.resize((20, 20), Image.NEAREST) == im.resize((20, 20))

Tests/test_image_split.py

@@ -9,25 +9,25 @@ class TestImageSplit(PillowTestCase):
             layers = hopper(mode).split()
             return [(i.mode, i.size[0], i.size[1]) for i in layers]
 
-        self.assertEqual(split("1"), [("1", 128, 128)])
-        self.assertEqual(split("L"), [("L", 128, 128)])
-        self.assertEqual(split("I"), [("I", 128, 128)])
-        self.assertEqual(split("F"), [("F", 128, 128)])
-        self.assertEqual(split("P"), [("P", 128, 128)])
-        self.assertEqual(
-            split("RGB"), [("L", 128, 128), ("L", 128, 128), ("L", 128, 128)]
-        )
-        self.assertEqual(
-            split("RGBA"),
-            [("L", 128, 128), ("L", 128, 128), ("L", 128, 128), ("L", 128, 128)],
-        )
-        self.assertEqual(
-            split("CMYK"),
-            [("L", 128, 128), ("L", 128, 128), ("L", 128, 128), ("L", 128, 128)],
-        )
-        self.assertEqual(
-            split("YCbCr"), [("L", 128, 128), ("L", 128, 128), ("L", 128, 128)]
-        )
+        assert split("1") == [("1", 128, 128)]
+        assert split("L") == [("L", 128, 128)]
+        assert split("I") == [("I", 128, 128)]
+        assert split("F") == [("F", 128, 128)]
+        assert split("P") == [("P", 128, 128)]
+        assert split("RGB") == [("L", 128, 128), ("L", 128, 128), ("L", 128, 128)]
+        assert split("RGBA") == [
+            ("L", 128, 128),
+            ("L", 128, 128),
+            ("L", 128, 128),
+            ("L", 128, 128),
+        ]
+        assert split("CMYK") == [
+            ("L", 128, 128),
+            ("L", 128, 128),
+            ("L", 128, 128),
+            ("L", 128, 128),
+        ]
+        assert split("YCbCr") == [("L", 128, 128), ("L", 128, 128), ("L", 128, 128)]
 
     def test_split_merge(self):
         def split_merge(mode):
@@ -54,9 +54,9 @@ class TestImageSplit(PillowTestCase):
             with Image.open(test_file) as im:
                 return len(im.split())
 
-        self.assertEqual(split_open("1"), 1)
-        self.assertEqual(split_open("L"), 1)
-        self.assertEqual(split_open("P"), 1)
-        self.assertEqual(split_open("RGB"), 3)
+        assert split_open("1") == 1
+        assert split_open("L") == 1
+        assert split_open("P") == 1
+        assert split_open("RGB") == 3
         if features.check("zlib"):
-            self.assertEqual(split_open("RGBA"), 4)
+            assert split_open("RGBA") == 4

Tests/test_image_transform.py

@@ -1,5 +1,6 @@
 import math
 
+import pytest
 from PIL import Image, ImageTransform
 
 from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
@@ -24,11 +25,11 @@ class TestImageTransform(PillowTestCase):
         comment = b"File written by Adobe Photoshop\xa8 4.0"
 
         with Image.open("Tests/images/hopper.gif") as im:
-            self.assertEqual(im.info["comment"], comment)
+            assert im.info["comment"] == comment
 
             transform = ImageTransform.ExtentTransform((0, 0, 0, 0))
             new_im = im.transform((100, 100), transform)
-        self.assertEqual(new_im.info["comment"], comment)
+        assert new_im.info["comment"] == comment
 
     def test_extent(self):
         im = hopper("RGB")
@@ -79,7 +80,7 @@ class TestImageTransform(PillowTestCase):
                 fillcolor="red",
             )
 
-            self.assertEqual(transformed.getpixel((w - 1, h - 1)), pixel)
+            assert transformed.getpixel((w - 1, h - 1)) == pixel
 
     def test_mesh(self):
         # this should be a checkerboard of halfsized hoppers in ul, lr
@@ -126,7 +127,7 @@ class TestImageTransform(PillowTestCase):
         im_background.paste(im, (0, 0), im)
 
         hist = im_background.histogram()
-        self.assertEqual(40 * 10, hist[-1])
+        assert 40 * 10 == hist[-1]
 
     def test_alpha_premult_resize(self):
         def op(im, sz):
@@ -165,20 +166,15 @@ class TestImageTransform(PillowTestCase):
 
     def test_missing_method_data(self):
         with hopper() as im:
-            self.assertRaises(ValueError, im.transform, (100, 100), None)
+            with pytest.raises(ValueError):
+                im.transform((100, 100), None)
 
     def test_unknown_resampling_filter(self):
         with hopper() as im:
             (w, h) = im.size
             for resample in (Image.BOX, "unknown"):
-                self.assertRaises(
-                    ValueError,
-                    im.transform,
-                    (100, 100),
-                    Image.EXTENT,
-                    (0, 0, w, h),
-                    resample,
-                )
+                with pytest.raises(ValueError):
+                    im.transform((100, 100), Image.EXTENT, (0, 0, w, h), resample)
 
 
 class TestImageTransformAffine(PillowTestCase):

Tests/test_imagefile.py

@@ -1,5 +1,6 @@
 from io import BytesIO
 
+import pytest
 from PIL import EpsImagePlugin, Image, ImageFile, features
 
 from .helper import (
@@ -71,14 +72,15 @@ class TestImageFile(PillowTestCase):
             im1, im2 = roundtrip("JPEG")  # lossy compression
             assert_image(im1, im2.mode, im2.size)
 
-        self.assertRaises(IOError, roundtrip, "PDF")
+        with pytest.raises(IOError):
+            roundtrip("PDF")
 
     def test_ico(self):
         with open("Tests/images/python.ico", "rb") as f:
             data = f.read()
         with ImageFile.Parser() as p:
             p.feed(data)
-            self.assertEqual((48, 48), p.image.size)
+            assert (48, 48) == p.image.size
 
     @skip_unless_feature("zlib")
     def test_safeblock(self):
@@ -93,10 +95,11 @@ class TestImageFile(PillowTestCase):
         assert_image_equal(im1, im2)
 
     def test_raise_ioerror(self):
-        self.assertRaises(IOError, ImageFile.raise_ioerror, 1)
+        with pytest.raises(IOError):
+            ImageFile.raise_ioerror(1)
 
     def test_raise_typeerror(self):
-        with self.assertRaises(TypeError):
+        with pytest.raises(TypeError):
             parser = ImageFile.Parser()
             parser.feed(1)
 
@@ -105,17 +108,17 @@ class TestImageFile(PillowTestCase):
             input = f.read()
         p = ImageFile.Parser()
         p.feed(input)
-        with self.assertRaises(IOError):
+        with pytest.raises(IOError):
             p.close()
 
     @skip_unless_feature("zlib")
     def test_truncated_with_errors(self):
         with Image.open("Tests/images/truncated_image.png") as im:
-            with self.assertRaises(IOError):
+            with pytest.raises(IOError):
                 im.load()
 
             # Test that the error is raised if loaded a second time
-            with self.assertRaises(IOError):
+            with pytest.raises(IOError):
                 im.load()
 
     @skip_unless_feature("zlib")
@@ -130,7 +133,7 @@ class TestImageFile(PillowTestCase):
     @skip_unless_feature("zlib")
     def test_broken_datastream_with_errors(self):
         with Image.open("Tests/images/broken_data_stream.png") as im:
-            with self.assertRaises(IOError):
+            with pytest.raises(IOError):
                 im.load()
 
     @skip_unless_feature("zlib")
@@ -179,12 +182,13 @@ class TestPyDecoder(PillowTestCase):
 
         im.load()
 
-        self.assertEqual(d.state.xoff, xoff)
-        self.assertEqual(d.state.yoff, yoff)
-        self.assertEqual(d.state.xsize, xsize)
-        self.assertEqual(d.state.ysize, ysize)
+        assert d.state.xoff == xoff
+        assert d.state.yoff == yoff
+        assert d.state.xsize == xsize
+        assert d.state.ysize == ysize
 
-        self.assertRaises(ValueError, d.set_as_raw, b"\x00")
+        with pytest.raises(ValueError):
+            d.set_as_raw(b"\x00")
 
     def test_extents_none(self):
         buf = BytesIO(b"\x00" * 255)
@@ -195,10 +199,10 @@ class TestPyDecoder(PillowTestCase):
 
         im.load()
 
-        self.assertEqual(d.state.xoff, 0)
-        self.assertEqual(d.state.yoff, 0)
-        self.assertEqual(d.state.xsize, 200)
-        self.assertEqual(d.state.ysize, 200)
+        assert d.state.xoff == 0
+        assert d.state.yoff == 0
+        assert d.state.xsize == 200
+        assert d.state.ysize == 200
 
     def test_negsize(self):
         buf = BytesIO(b"\x00" * 255)
@@ -207,10 +211,12 @@ class TestPyDecoder(PillowTestCase):
         im.tile = [("MOCK", (xoff, yoff, -10, yoff + ysize), 32, None)]
         self.get_decoder()
 
-        self.assertRaises(ValueError, im.load)
+        with pytest.raises(ValueError):
+            im.load()
 
         im.tile = [("MOCK", (xoff, yoff, xoff + xsize, -10), 32, None)]
-        self.assertRaises(ValueError, im.load)
+        with pytest.raises(ValueError):
+            im.load()
 
     def test_oversize(self):
         buf = BytesIO(b"\x00" * 255)
@@ -219,25 +225,27 @@ class TestPyDecoder(PillowTestCase):
         im.tile = [("MOCK", (xoff, yoff, xoff + xsize + 100, yoff + ysize), 32, None)]
         self.get_decoder()
 
-        self.assertRaises(ValueError, im.load)
+        with pytest.raises(ValueError):
+            im.load()
 
         im.tile = [("MOCK", (xoff, yoff, xoff + xsize, yoff + ysize + 100), 32, None)]
-        self.assertRaises(ValueError, im.load)
+        with pytest.raises(ValueError):
+            im.load()
 
     def test_no_format(self):
         buf = BytesIO(b"\x00" * 255)
 
         im = MockImageFile(buf)
-        self.assertIsNone(im.format)
-        self.assertIsNone(im.get_format_mimetype())
+        assert im.format is None
+        assert im.get_format_mimetype() is None
 
     def test_exif_jpeg(self):
         with Image.open("Tests/images/exif-72dpi-int.jpg") as im:  # Little endian
             exif = im.getexif()
-            self.assertNotIn(258, exif)
-            self.assertIn(40960, exif)
-            self.assertEqual(exif[40963], 450)
-            self.assertEqual(exif[11], "gThumb 3.0.1")
+            assert 258 not in exif
+            assert 40960 in exif
+            assert exif[40963] == 450
+            assert exif[11] == "gThumb 3.0.1"
 
             out = self.tempfile("temp.jpg")
             exif[258] = 8
@@ -247,17 +255,17 @@ class TestPyDecoder(PillowTestCase):
             im.save(out, exif=exif)
         with Image.open(out) as reloaded:
             reloaded_exif = reloaded.getexif()
-            self.assertEqual(reloaded_exif[258], 8)
-            self.assertNotIn(40960, exif)
-            self.assertEqual(reloaded_exif[40963], 455)
-            self.assertEqual(exif[11], "Pillow test")
+            assert reloaded_exif[258] == 8
+            assert 40960 not in exif
+            assert reloaded_exif[40963] == 455
+            assert exif[11] == "Pillow test"
 
         with Image.open("Tests/images/no-dpi-in-exif.jpg") as im:  # Big endian
             exif = im.getexif()
-            self.assertNotIn(258, exif)
-            self.assertIn(40962, exif)
-            self.assertEqual(exif[40963], 200)
-            self.assertEqual(exif[305], "Adobe Photoshop CC 2017 (Macintosh)")
+            assert 258 not in exif
+            assert 40962 in exif
+            assert exif[40963] == 200
+            assert exif[305] == "Adobe Photoshop CC 2017 (Macintosh)"
 
             out = self.tempfile("temp.jpg")
             exif[258] = 8
@@ -267,17 +275,17 @@ class TestPyDecoder(PillowTestCase):
             im.save(out, exif=exif)
         with Image.open(out) as reloaded:
             reloaded_exif = reloaded.getexif()
-            self.assertEqual(reloaded_exif[258], 8)
-            self.assertNotIn(40960, exif)
-            self.assertEqual(reloaded_exif[40963], 455)
-            self.assertEqual(exif[305], "Pillow test")
+            assert reloaded_exif[258] == 8
+            assert 40960 not in exif
+            assert reloaded_exif[40963] == 455
+            assert exif[305] == "Pillow test"
 
     @skip_unless_feature("webp")
     @skip_unless_feature("webp_anim")
     def test_exif_webp(self):
         with Image.open("Tests/images/hopper.webp") as im:
             exif = im.getexif()
-            self.assertEqual(exif, {})
+            assert exif == {}
 
             out = self.tempfile("temp.webp")
             exif[258] = 8
@@ -287,9 +295,9 @@ class TestPyDecoder(PillowTestCase):
             def check_exif():
                 with Image.open(out) as reloaded:
                     reloaded_exif = reloaded.getexif()
-                    self.assertEqual(reloaded_exif[258], 8)
-                    self.assertEqual(reloaded_exif[40963], 455)
-                    self.assertEqual(exif[305], "Pillow test")
+                    assert reloaded_exif[258] == 8
+                    assert reloaded_exif[40963] == 455
+                    assert exif[305] == "Pillow test"
 
             im.save(out, exif=exif)
             check_exif()
@@ -299,7 +307,7 @@ class TestPyDecoder(PillowTestCase):
     def test_exif_png(self):
         with Image.open("Tests/images/exif.png") as im:
             exif = im.getexif()
-            self.assertEqual(exif, {274: 1})
+            assert exif == {274: 1}
 
             out = self.tempfile("temp.png")
             exif[258] = 8
@@ -310,11 +318,14 @@ class TestPyDecoder(PillowTestCase):
 
         with Image.open(out) as reloaded:
             reloaded_exif = reloaded.getexif()
-            self.assertEqual(reloaded_exif, {258: 8, 40963: 455, 305: "Pillow test"})
+            assert reloaded_exif == {258: 8, 40963: 455, 305: "Pillow test"}
 
     def test_exif_interop(self):
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
-            self.assertEqual(
-                exif.get_ifd(0xA005), {1: "R98", 2: b"0100", 4097: 2272, 4098: 1704}
-            )
+            assert exif.get_ifd(0xA005) == {
+                1: "R98",
+                2: b"0100",
+                4097: 2272,
+                4098: 1704,
+            }

Tests/test_imagefont.py

@@ -7,6 +7,7 @@ import unittest
 from io import BytesIO
 from unittest import mock
 
+import pytest
 from PIL import Image, ImageDraw, ImageFont
 
 from .helper import (
@@ -69,19 +70,19 @@ class TestImageFont(PillowTestCase):
 
     def test_font_properties(self):
         ttf = self.get_font()
-        self.assertEqual(ttf.path, FONT_PATH)
-        self.assertEqual(ttf.size, FONT_SIZE)
+        assert ttf.path == FONT_PATH
+        assert ttf.size == FONT_SIZE
 
         ttf_copy = ttf.font_variant()
-        self.assertEqual(ttf_copy.path, FONT_PATH)
-        self.assertEqual(ttf_copy.size, FONT_SIZE)
+        assert ttf_copy.path == FONT_PATH
+        assert ttf_copy.size == FONT_SIZE
 
         ttf_copy = ttf.font_variant(size=FONT_SIZE + 1)
-        self.assertEqual(ttf_copy.size, FONT_SIZE + 1)
+        assert ttf_copy.size == FONT_SIZE + 1
 
         second_font_path = "Tests/fonts/DejaVuSans.ttf"
         ttf_copy = ttf.font_variant(font=second_font_path)
-        self.assertEqual(ttf_copy.path, second_font_path)
+        assert ttf_copy.path == second_font_path
 
     def test_font_with_name(self):
         self.get_font()
@@ -100,7 +101,8 @@ class TestImageFont(PillowTestCase):
         # Usage note:  making two fonts from the same buffer fails.
         # shared_bytes = self._font_as_bytes()
         # self._render(shared_bytes)
-        # self.assertRaises(Exception, _render, shared_bytes)
+        # with pytest.raises(Exception):
+        #   _render(shared_bytes)
 
     def test_font_with_open_file(self):
         with open(FONT_PATH, "rb") as f:
@@ -126,7 +128,7 @@ class TestImageFont(PillowTestCase):
         finally:
             ImageFont.core.HAVE_RAQM = have_raqm
 
-        self.assertEqual(ttf.layout_engine, ImageFont.LAYOUT_BASIC)
+        assert ttf.layout_engine == ImageFont.LAYOUT_BASIC
 
     def _render(self, font):
         txt = "Hello World!"
@@ -222,14 +224,8 @@ class TestImageFont(PillowTestCase):
         ttf = self.get_font()
 
         # Act/Assert
-        self.assertRaises(
-            ValueError,
-            draw.multiline_text,
-            (0, 0),
-            TEST_TEXT,
-            font=ttf,
-            align="unknown",
-        )
+        with pytest.raises(ValueError):
+            draw.multiline_text((0, 0), TEST_TEXT, font=ttf, align="unknown")
 
     def test_draw_align(self):
         im = Image.new("RGB", (300, 100), "white")
@@ -244,14 +240,13 @@ class TestImageFont(PillowTestCase):
         draw = ImageDraw.Draw(im)
 
         # Test that textsize() correctly connects to multiline_textsize()
-        self.assertEqual(
-            draw.textsize(TEST_TEXT, font=ttf),
-            draw.multiline_textsize(TEST_TEXT, font=ttf),
+        assert draw.textsize(TEST_TEXT, font=ttf) == draw.multiline_textsize(
+            TEST_TEXT, font=ttf
         )
 
         # Test that multiline_textsize corresponds to ImageFont.textsize()
         # for single line text
-        self.assertEqual(ttf.getsize("A"), draw.multiline_textsize("A", font=ttf))
+        assert ttf.getsize("A") == draw.multiline_textsize("A", font=ttf)
 
         # Test that textsize() can pass on additional arguments
         # to multiline_textsize()
@@ -263,9 +258,9 @@ class TestImageFont(PillowTestCase):
         im = Image.new(mode="RGB", size=(300, 100))
         draw = ImageDraw.Draw(im)
 
-        self.assertEqual(
-            draw.textsize("longest line", font=ttf)[0],
-            draw.multiline_textsize("longest line\nline", font=ttf)[0],
+        assert (
+            draw.textsize("longest line", font=ttf)[0]
+            == draw.multiline_textsize("longest line\nline", font=ttf)[0]
         )
 
     def test_multiline_spacing(self):
@@ -299,8 +294,8 @@ class TestImageFont(PillowTestCase):
         box_size_b = draw.textsize(word)
 
         # Check (w,h) of box a is (h,w) of box b
-        self.assertEqual(box_size_a[0], box_size_b[1])
-        self.assertEqual(box_size_a[1], box_size_b[0])
+        assert box_size_a[0] == box_size_b[1]
+        assert box_size_a[1] == box_size_b[0]
 
     def test_unrotated_transposed_font(self):
         img_grey = Image.new("L", (100, 100))
@@ -320,7 +315,7 @@ class TestImageFont(PillowTestCase):
         box_size_b = draw.textsize(word)
 
         # Check boxes a and b are same size
-        self.assertEqual(box_size_a, box_size_b)
+        assert box_size_a == box_size_b
 
     def test_rotated_transposed_font_get_mask(self):
         # Arrange
@@ -333,7 +328,7 @@ class TestImageFont(PillowTestCase):
         mask = transposed_font.getmask(text)
 
         # Assert
-        self.assertEqual(mask.size, (13, 108))
+        assert mask.size == (13, 108)
 
     def test_unrotated_transposed_font_get_mask(self):
         # Arrange
@@ -346,7 +341,7 @@ class TestImageFont(PillowTestCase):
         mask = transposed_font.getmask(text)
 
         # Assert
-        self.assertEqual(mask.size, (108, 13))
+        assert mask.size == (108, 13)
 
     def test_free_type_font_get_name(self):
         # Arrange
@@ -356,7 +351,7 @@ class TestImageFont(PillowTestCase):
         name = font.getname()
 
         # Assert
-        self.assertEqual(("FreeMono", "Regular"), name)
+        assert ("FreeMono", "Regular") == name
 
     def test_free_type_font_get_metrics(self):
         # Arrange
@@ -366,9 +361,9 @@ class TestImageFont(PillowTestCase):
         ascent, descent = font.getmetrics()
 
         # Assert
-        self.assertIsInstance(ascent, int)
-        self.assertIsInstance(descent, int)
-        self.assertEqual((ascent, descent), (16, 4))  # too exact check?
+        assert isinstance(ascent, int)
+        assert isinstance(descent, int)
+        assert (ascent, descent) == (16, 4)  # too exact check?
 
     def test_free_type_font_get_offset(self):
         # Arrange
@@ -379,7 +374,7 @@ class TestImageFont(PillowTestCase):
         offset = font.getoffset(text)
 
         # Assert
-        self.assertEqual(offset, (0, 3))
+        assert offset == (0, 3)
 
     def test_free_type_font_get_mask(self):
         # Arrange
@@ -390,19 +385,22 @@ class TestImageFont(PillowTestCase):
         mask = font.getmask(text)
 
         # Assert
-        self.assertEqual(mask.size, (108, 13))
+        assert mask.size == (108, 13)
 
     def test_load_path_not_found(self):
         # Arrange
         filename = "somefilenamethatdoesntexist.ttf"
 
         # Act/Assert
-        self.assertRaises(IOError, ImageFont.load_path, filename)
-        self.assertRaises(IOError, ImageFont.truetype, filename)
+        with pytest.raises(IOError):
+            ImageFont.load_path(filename)
+        with pytest.raises(IOError):
+            ImageFont.truetype(filename)
 
     def test_load_non_font_bytes(self):
         with open("Tests/images/hopper.jpg", "rb") as f:
-            self.assertRaises(IOError, ImageFont.truetype, f)
+            with pytest.raises(IOError):
+                ImageFont.truetype(f)
 
     def test_default_font(self):
         # Arrange
@@ -424,7 +422,7 @@ class TestImageFont(PillowTestCase):
         # issue #2614
         font = self.get_font()
         # should not crash.
-        self.assertEqual((0, 0), font.getsize(""))
+        assert (0, 0) == font.getsize("")
 
     def test_render_empty(self):
         # issue 2666
@@ -440,7 +438,7 @@ class TestImageFont(PillowTestCase):
         # should not segfault, should return UnicodeDecodeError
         # issue #2826
         font = ImageFont.load_default()
-        with self.assertRaises(UnicodeEncodeError):
+        with pytest.raises(UnicodeEncodeError):
             font.getsize("’")
 
     @unittest.skipIf(is_pypy(), "failing on PyPy")
@@ -478,7 +476,7 @@ class TestImageFont(PillowTestCase):
                 font = ImageFont.truetype(fontname)
                 # Make sure it's loaded
                 name = font.getname()
-                self.assertEqual(("FreeMono", "Regular"), name)
+                assert ("FreeMono", "Regular") == name
 
     @unittest.skipIf(is_win32(), "requires Unix or macOS")
     def test_find_linux_font(self):
@@ -561,24 +559,24 @@ class TestImageFont(PillowTestCase):
         t = self.get_font()
 
         # Act / Assert
-        self.assertEqual(t.getmetrics(), (16, 4))
-        self.assertEqual(t.font.ascent, 16)
-        self.assertEqual(t.font.descent, 4)
-        self.assertEqual(t.font.height, 20)
-        self.assertEqual(t.font.x_ppem, 20)
-        self.assertEqual(t.font.y_ppem, 20)
-        self.assertEqual(t.font.glyphs, 4177)
-        self.assertEqual(t.getsize("A"), (12, 16))
-        self.assertEqual(t.getsize("AB"), (24, 16))
-        self.assertEqual(t.getsize("M"), self.metrics["getters"])
-        self.assertEqual(t.getsize("y"), (12, 20))
-        self.assertEqual(t.getsize("a"), (12, 16))
-        self.assertEqual(t.getsize_multiline("A"), (12, 16))
-        self.assertEqual(t.getsize_multiline("AB"), (24, 16))
-        self.assertEqual(t.getsize_multiline("a"), (12, 16))
-        self.assertEqual(t.getsize_multiline("ABC\n"), (36, 36))
-        self.assertEqual(t.getsize_multiline("ABC\nA"), (36, 36))
-        self.assertEqual(t.getsize_multiline("ABC\nAaaa"), (48, 36))
+        assert t.getmetrics() == (16, 4)
+        assert t.font.ascent == 16
+        assert t.font.descent == 4
+        assert t.font.height == 20
+        assert t.font.x_ppem == 20
+        assert t.font.y_ppem == 20
+        assert t.font.glyphs == 4177
+        assert t.getsize("A") == (12, 16)
+        assert t.getsize("AB") == (24, 16)
+        assert t.getsize("M") == self.metrics["getters"]
+        assert t.getsize("y") == (12, 20)
+        assert t.getsize("a") == (12, 16)
+        assert t.getsize_multiline("A") == (12, 16)
+        assert t.getsize_multiline("AB") == (24, 16)
+        assert t.getsize_multiline("a") == (12, 16)
+        assert t.getsize_multiline("ABC\n") == (36, 36)
+        assert t.getsize_multiline("ABC\nA") == (36, 36)
+        assert t.getsize_multiline("ABC\nAaaa") == (48, 36)
 
     def test_getsize_stroke(self):
         # Arrange
@@ -586,13 +584,13 @@ class TestImageFont(PillowTestCase):
 
         # Act / Assert
         for stroke_width in [0, 2]:
-            self.assertEqual(
-                t.getsize("A", stroke_width=stroke_width),
-                (12 + stroke_width * 2, 16 + stroke_width * 2),
+            assert t.getsize("A", stroke_width=stroke_width) == (
+                12 + stroke_width * 2,
+                16 + stroke_width * 2,
             )
-            self.assertEqual(
-                t.getsize_multiline("ABC\nAaaa", stroke_width=stroke_width),
-                (48 + stroke_width * 2, 36 + stroke_width * 4),
+            assert t.getsize_multiline("ABC\nAaaa", stroke_width=stroke_width) == (
+                48 + stroke_width * 2,
+                36 + stroke_width * 4,
             )
 
     def test_complex_font_settings(self):
@@ -600,81 +598,80 @@ class TestImageFont(PillowTestCase):
         t = self.get_font()
         # Act / Assert
         if t.layout_engine == ImageFont.LAYOUT_BASIC:
-            self.assertRaises(KeyError, t.getmask, "абвг", direction="rtl")
-            self.assertRaises(KeyError, t.getmask, "абвг", features=["-kern"])
-            self.assertRaises(KeyError, t.getmask, "абвг", language="sr")
+            with pytest.raises(KeyError):
+                t.getmask("абвг", direction="rtl")
+            with pytest.raises(KeyError):
+                t.getmask("абвг", features=["-kern"])
+            with pytest.raises(KeyError):
+                t.getmask("абвг", language="sr")
 
     def test_variation_get(self):
         font = self.get_font()
 
         freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
         if freetype < "2.9.1":
-            self.assertRaises(NotImplementedError, font.get_variation_names)
-            self.assertRaises(NotImplementedError, font.get_variation_axes)
+            with pytest.raises(NotImplementedError):
+                font.get_variation_names()
+            with pytest.raises(NotImplementedError):
+                font.get_variation_axes()
             return
 
-        self.assertRaises(IOError, font.get_variation_names)
-        self.assertRaises(IOError, font.get_variation_axes)
+        with pytest.raises(IOError):
+            font.get_variation_names()
+        with pytest.raises(IOError):
+            font.get_variation_axes()
 
         font = ImageFont.truetype("Tests/fonts/AdobeVFPrototype.ttf")
-        self.assertEqual(
-            font.get_variation_names(),
-            [
-                b"ExtraLight",
-                b"Light",
-                b"Regular",
-                b"Semibold",
-                b"Bold",
-                b"Black",
-                b"Black Medium Contrast",
-                b"Black High Contrast",
-                b"Default",
-            ],
-        )
-        self.assertEqual(
-            font.get_variation_axes(),
-            [
-                {"name": b"Weight", "minimum": 200, "maximum": 900, "default": 389},
-                {"name": b"Contrast", "minimum": 0, "maximum": 100, "default": 0},
-            ],
-        )
+        assert font.get_variation_names(), [
+            b"ExtraLight",
+            b"Light",
+            b"Regular",
+            b"Semibold",
+            b"Bold",
+            b"Black",
+            b"Black Medium Contrast",
+            b"Black High Contrast",
+            b"Default",
+        ]
+        assert font.get_variation_axes() == [
+            {"name": b"Weight", "minimum": 200, "maximum": 900, "default": 389},
+            {"name": b"Contrast", "minimum": 0, "maximum": 100, "default": 0},
+        ]
 
         font = ImageFont.truetype("Tests/fonts/TINY5x3GX.ttf")
-        self.assertEqual(
-            font.get_variation_names(),
-            [
-                b"20",
-                b"40",
-                b"60",
-                b"80",
-                b"100",
-                b"120",
-                b"140",
-                b"160",
-                b"180",
-                b"200",
-                b"220",
-                b"240",
-                b"260",
-                b"280",
-                b"300",
-                b"Regular",
-            ],
-        )
-        self.assertEqual(
-            font.get_variation_axes(),
-            [{"name": b"Size", "minimum": 0, "maximum": 300, "default": 0}],
-        )
+        assert font.get_variation_names() == [
+            b"20",
+            b"40",
+            b"60",
+            b"80",
+            b"100",
+            b"120",
+            b"140",
+            b"160",
+            b"180",
+            b"200",
+            b"220",
+            b"240",
+            b"260",
+            b"280",
+            b"300",
+            b"Regular",
+        ]
+        assert font.get_variation_axes() == [
+            {"name": b"Size", "minimum": 0, "maximum": 300, "default": 0}
+        ]
 
     def test_variation_set_by_name(self):
         font = self.get_font()
 
         freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
         if freetype < "2.9.1":
-            self.assertRaises(NotImplementedError, font.set_variation_by_name, "Bold")
+            with pytest.raises(NotImplementedError):
+                font.set_variation_by_name("Bold")
             return
 
-        self.assertRaises(IOError, font.set_variation_by_name, "Bold")
+        with pytest.raises(IOError):
+            font.set_variation_by_name("Bold")
 
         def _check_text(font, path, epsilon):
             im = Image.new("RGB", (100, 75), "white")
@@ -701,10 +698,12 @@ class TestImageFont(PillowTestCase):
 
         freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
         if freetype < "2.9.1":
-            self.assertRaises(NotImplementedError, font.set_variation_by_axes, [100])
+            with pytest.raises(NotImplementedError):
+                font.set_variation_by_axes([100])
             return
 
-        self.assertRaises(IOError, font.set_variation_by_axes, [500, 50])
+        with pytest.raises(IOError):
+            font.set_variation_by_axes([500, 50])
 
         def _check_text(font, path, epsilon):
             im = Image.new("RGB", (100, 75), "white")

Tests/test_imagefontctl.py

@@ -140,7 +140,7 @@ class TestImagecomplextext(PillowTestCase):
             assert_image_similar(im, target_img, 0.5)
 
         liga_size = ttf.getsize("fi", features=["-liga"])
-        self.assertEqual(liga_size, (13, 19))
+        assert liga_size == (13, 19)
 
     def test_kerning_features(self):
         ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE)

Tests/test_imagegrab.py

@@ -59,7 +59,7 @@ class TestImageGrabImport(PillowTestCase):
 
         # Assert
         if sys.platform in ["win32", "darwin"]:
-            self.assertIsNone(exception)
+            assert exception is None
         else:
-            self.assertIsInstance(exception, ImportError)
-            self.assertEqual(str(exception), "ImageGrab is macOS and Windows only")
+            assert isinstance(exception, ImportError)
+            assert str(exception) == "ImageGrab is macOS and Windows only"

Tests/test_imagemorph.py

@@ -1,4 +1,5 @@
 # Test the ImageMorphology functionality
+import pytest
 from PIL import Image, ImageMorph, _imagingmorph
 
 from .helper import PillowTestCase, assert_image_equal, hopper
@@ -45,10 +46,10 @@ class MorphTests(PillowTestCase):
         return self.img_to_string(self.string_to_img(im))
 
     def assert_img_equal(self, A, B):
-        self.assertEqual(self.img_to_string(A), self.img_to_string(B))
+        assert self.img_to_string(A) == self.img_to_string(B)
 
     def assert_img_equal_img_string(self, A, Bstring):
-        self.assertEqual(self.img_to_string(A), self.img_string_normalize(Bstring))
+        assert self.img_to_string(A) == self.img_string_normalize(Bstring)
 
     def test_str_to_img(self):
         with Image.open("Tests/images/morph_a.png") as im:
@@ -65,30 +66,30 @@ class MorphTests(PillowTestCase):
     def test_lut(self):
         for op in ("corner", "dilation4", "dilation8", "erosion4", "erosion8", "edge"):
             lb = ImageMorph.LutBuilder(op_name=op)
-            self.assertIsNone(lb.get_lut())
+            assert lb.get_lut() is None
 
             lut = lb.build_lut()
             with open("Tests/images/%s.lut" % op, "rb") as f:
-                self.assertEqual(lut, bytearray(f.read()))
+                assert lut == bytearray(f.read())
 
     def test_no_operator_loaded(self):
         mop = ImageMorph.MorphOp()
-        with self.assertRaises(Exception) as e:
+        with pytest.raises(Exception) as e:
             mop.apply(None)
-        self.assertEqual(str(e.exception), "No operator loaded")
-        with self.assertRaises(Exception) as e:
+        assert str(e.value) == "No operator loaded"
+        with pytest.raises(Exception) as e:
             mop.match(None)
-        self.assertEqual(str(e.exception), "No operator loaded")
-        with self.assertRaises(Exception) as e:
+        assert str(e.value) == "No operator loaded"
+        with pytest.raises(Exception) as e:
             mop.save_lut(None)
-        self.assertEqual(str(e.exception), "No operator loaded")
+        assert str(e.value) == "No operator loaded"
 
     # Test the named patterns
     def test_erosion8(self):
         # erosion8
         mop = ImageMorph.MorphOp(op_name="erosion8")
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 8)
+        assert count == 8
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -106,7 +107,7 @@ class MorphTests(PillowTestCase):
         # dialation8
         mop = ImageMorph.MorphOp(op_name="dilation8")
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 16)
+        assert count == 16
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -124,7 +125,7 @@ class MorphTests(PillowTestCase):
         # erosion4
         mop = ImageMorph.MorphOp(op_name="dilation4")
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 12)
+        assert count == 12
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -142,7 +143,7 @@ class MorphTests(PillowTestCase):
         # edge
         mop = ImageMorph.MorphOp(op_name="edge")
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 1)
+        assert count == 1
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -160,7 +161,7 @@ class MorphTests(PillowTestCase):
         # Create a corner detector pattern
         mop = ImageMorph.MorphOp(patterns=["1:(... ... ...)->0", "4:(00. 01. ...)->1"])
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 5)
+        assert count == 5
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -176,18 +177,18 @@ class MorphTests(PillowTestCase):
 
         # Test the coordinate counting with the same operator
         coords = mop.match(self.A)
-        self.assertEqual(len(coords), 4)
-        self.assertEqual(tuple(coords), ((2, 2), (4, 2), (2, 4), (4, 4)))
+        assert len(coords) == 4
+        assert tuple(coords) == ((2, 2), (4, 2), (2, 4), (4, 4))
 
         coords = mop.get_on_pixels(Aout)
-        self.assertEqual(len(coords), 4)
-        self.assertEqual(tuple(coords), ((2, 2), (4, 2), (2, 4), (4, 4)))
+        assert len(coords) == 4
+        assert tuple(coords) == ((2, 2), (4, 2), (2, 4), (4, 4))
 
     def test_mirroring(self):
         # Test 'M' for mirroring
         mop = ImageMorph.MorphOp(patterns=["1:(... ... ...)->0", "M:(00. 01. ...)->1"])
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 7)
+        assert count == 7
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -205,7 +206,7 @@ class MorphTests(PillowTestCase):
         # Test 'N' for negate
         mop = ImageMorph.MorphOp(patterns=["1:(... ... ...)->0", "N:(00. 01. ...)->1"])
         count, Aout = mop.apply(self.A)
-        self.assertEqual(count, 8)
+        assert count == 8
         self.assert_img_equal_img_string(
             Aout,
             """
@@ -223,44 +224,36 @@ class MorphTests(PillowTestCase):
         im = hopper("RGB")
         mop = ImageMorph.MorphOp(op_name="erosion8")
 
-        with self.assertRaises(Exception) as e:
+        with pytest.raises(Exception) as e:
             mop.apply(im)
-        self.assertEqual(
-            str(e.exception), "Image must be binary, meaning it must use mode L"
-        )
-        with self.assertRaises(Exception) as e:
+        assert str(e.value) == "Image must be binary, meaning it must use mode L"
+        with pytest.raises(Exception) as e:
             mop.match(im)
-        self.assertEqual(
-            str(e.exception), "Image must be binary, meaning it must use mode L"
-        )
-        with self.assertRaises(Exception) as e:
+        assert str(e.value) == "Image must be binary, meaning it must use mode L"
+        with pytest.raises(Exception) as e:
             mop.get_on_pixels(im)
-        self.assertEqual(
-            str(e.exception), "Image must be binary, meaning it must use mode L"
-        )
+        assert str(e.value) == "Image must be binary, meaning it must use mode L"
 
     def test_add_patterns(self):
         # Arrange
         lb = ImageMorph.LutBuilder(op_name="corner")
-        self.assertEqual(lb.patterns, ["1:(... ... ...)->0", "4:(00. 01. ...)->1"])
+        assert lb.patterns == ["1:(... ... ...)->0", "4:(00. 01. ...)->1"]
         new_patterns = ["M:(00. 01. ...)->1", "N:(00. 01. ...)->1"]
 
         # Act
         lb.add_patterns(new_patterns)
 
         # Assert
-        self.assertEqual(
-            lb.patterns,
-            [
-                "1:(... ... ...)->0",
-                "4:(00. 01. ...)->1",
-                "M:(00. 01. ...)->1",
-                "N:(00. 01. ...)->1",
-            ],
-        )
+        assert lb.patterns == [
+            "1:(... ... ...)->0",
+            "4:(00. 01. ...)->1",
+            "M:(00. 01. ...)->1",
+            "N:(00. 01. ...)->1",
+        ]
 
     def test_unknown_pattern(self):
-        self.assertRaises(Exception, ImageMorph.LutBuilder, op_name="unknown")
+        with pytest.raises(Exception):
+            ImageMorph.LutBuilder(op_name="unknown")
 
     def test_pattern_syntax_error(self):
         # Arrange
@@ -269,11 +262,9 @@ class MorphTests(PillowTestCase):
         lb.add_patterns(new_patterns)
 
         # Act / Assert
-        with self.assertRaises(Exception) as e:
+        with pytest.raises(Exception) as e:
             lb.build_lut()
-        self.assertEqual(
-            str(e.exception), 'Syntax error in pattern "a pattern with a syntax error"'
-        )
+        assert str(e.value) == 'Syntax error in pattern "a pattern with a syntax error"'
 
     def test_load_invalid_mrl(self):
         # Arrange
@@ -281,9 +272,9 @@ class MorphTests(PillowTestCase):
         mop = ImageMorph.MorphOp()
 
         # Act / Assert
-        with self.assertRaises(Exception) as e:
+        with pytest.raises(Exception) as e:
             mop.load_lut(invalid_mrl)
-        self.assertEqual(str(e.exception), "Wrong size operator file!")
+        assert str(e.value) == "Wrong size operator file!"
 
     def test_roundtrip_mrl(self):
         # Arrange
@@ -296,7 +287,7 @@ class MorphTests(PillowTestCase):
         mop.load_lut(tempfile)
 
         # Act / Assert
-        self.assertEqual(mop.lut, initial_lut)
+        assert mop.lut == initial_lut
 
     def test_set_lut(self):
         # Arrange
@@ -308,20 +299,20 @@ class MorphTests(PillowTestCase):
         mop.set_lut(lut)
 
         # Assert
-        self.assertEqual(mop.lut, lut)
+        assert mop.lut == lut
 
     def test_wrong_mode(self):
         lut = ImageMorph.LutBuilder(op_name="corner").build_lut()
         imrgb = Image.new("RGB", (10, 10))
         iml = Image.new("L", (10, 10))
 
-        with self.assertRaises(RuntimeError):
+        with pytest.raises(RuntimeError):
             _imagingmorph.apply(bytes(lut), imrgb.im.id, iml.im.id)
 
-        with self.assertRaises(RuntimeError):
+        with pytest.raises(RuntimeError):
             _imagingmorph.apply(bytes(lut), iml.im.id, imrgb.im.id)
 
-        with self.assertRaises(RuntimeError):
+        with pytest.raises(RuntimeError):
             _imagingmorph.match(bytes(lut), imrgb.im.id)
 
         # Should not raise

Tests/test_imageops_usm.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, ImageFilter
 
 from .helper import PillowTestCase
@@ -15,44 +16,52 @@ class TestImageOpsUsm(PillowTestCase):
 
         test_filter = ImageFilter.GaussianBlur(2.0)
         i = self.im.filter(test_filter)
-        self.assertEqual(i.mode, "RGB")
-        self.assertEqual(i.size, (128, 128))
+        assert i.mode == "RGB"
+        assert i.size == (128, 128)
 
         test_filter = ImageFilter.UnsharpMask(2.0, 125, 8)
         i = self.im.filter(test_filter)
-        self.assertEqual(i.mode, "RGB")
-        self.assertEqual(i.size, (128, 128))
+        assert i.mode == "RGB"
+        assert i.size == (128, 128)
 
     def test_usm_formats(self):
 
         usm = ImageFilter.UnsharpMask
-        self.assertRaises(ValueError, self.im.convert("1").filter, usm)
+        with pytest.raises(ValueError):
+            self.im.convert("1").filter(usm)
         self.im.convert("L").filter(usm)
-        self.assertRaises(ValueError, self.im.convert("I").filter, usm)
-        self.assertRaises(ValueError, self.im.convert("F").filter, usm)
+        with pytest.raises(ValueError):
+            self.im.convert("I").filter(usm)
+        with pytest.raises(ValueError):
+            self.im.convert("F").filter(usm)
         self.im.convert("RGB").filter(usm)
         self.im.convert("RGBA").filter(usm)
         self.im.convert("CMYK").filter(usm)
-        self.assertRaises(ValueError, self.im.convert("YCbCr").filter, usm)
+        with pytest.raises(ValueError):
+            self.im.convert("YCbCr").filter(usm)
 
     def test_blur_formats(self):
 
         blur = ImageFilter.GaussianBlur
-        self.assertRaises(ValueError, self.im.convert("1").filter, blur)
+        with pytest.raises(ValueError):
+            self.im.convert("1").filter(blur)
         blur(self.im.convert("L"))
-        self.assertRaises(ValueError, self.im.convert("I").filter, blur)
-        self.assertRaises(ValueError, self.im.convert("F").filter, blur)
+        with pytest.raises(ValueError):
+            self.im.convert("I").filter(blur)
+        with pytest.raises(ValueError):
+            self.im.convert("F").filter(blur)
         self.im.convert("RGB").filter(blur)
         self.im.convert("RGBA").filter(blur)
         self.im.convert("CMYK").filter(blur)
-        self.assertRaises(ValueError, self.im.convert("YCbCr").filter, blur)
+        with pytest.raises(ValueError):
+            self.im.convert("YCbCr").filter(blur)
 
     def test_usm_accuracy(self):
 
         src = self.snakes.convert("RGB")
         i = src.filter(ImageFilter.UnsharpMask(5, 1024, 0))
         # Image should not be changed because it have only 0 and 255 levels.
-        self.assertEqual(i.tobytes(), src.tobytes())
+        assert i.tobytes() == src.tobytes()
 
     def test_blur_accuracy(self):
 
@@ -73,17 +82,17 @@ class TestImageOpsUsm(PillowTestCase):
             (4, 3, 2),
             (4, 2, 2),
         ]:
-            self.assertGreaterEqual(i.im.getpixel((x, y))[c], 250)
+            assert i.im.getpixel((x, y))[c] >= 250
         # Fuzzy match.
 
         def gp(x, y):
             return i.im.getpixel((x, y))
 
-        self.assertTrue(236 <= gp(7, 4)[0] <= 239)
-        self.assertTrue(236 <= gp(7, 5)[2] <= 239)
-        self.assertTrue(236 <= gp(7, 6)[2] <= 239)
-        self.assertTrue(236 <= gp(7, 7)[1] <= 239)
-        self.assertTrue(236 <= gp(8, 4)[0] <= 239)
-        self.assertTrue(236 <= gp(8, 5)[2] <= 239)
-        self.assertTrue(236 <= gp(8, 6)[2] <= 239)
-        self.assertTrue(236 <= gp(8, 7)[1] <= 239)
+        assert 236 <= gp(7, 4)[0] <= 239
+        assert 236 <= gp(7, 5)[2] <= 239
+        assert 236 <= gp(7, 6)[2] <= 239
+        assert 236 <= gp(7, 7)[1] <= 239
+        assert 236 <= gp(8, 4)[0] <= 239
+        assert 236 <= gp(8, 5)[2] <= 239
+        assert 236 <= gp(8, 6)[2] <= 239
+        assert 236 <= gp(8, 7)[1] <= 239

Tests/test_imagepalette.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, ImagePalette
 
 from .helper import PillowTestCase, assert_image_equal
@@ -7,9 +8,8 @@ class TestImagePalette(PillowTestCase):
     def test_sanity(self):
 
         ImagePalette.ImagePalette("RGB", list(range(256)) * 3)
-        self.assertRaises(
-            ValueError, ImagePalette.ImagePalette, "RGB", list(range(256)) * 2
-        )
+        with pytest.raises(ValueError):
+            ImagePalette.ImagePalette("RGB", list(range(256)) * 2)
 
     def test_getcolor(self):
 
@@ -19,11 +19,13 @@ class TestImagePalette(PillowTestCase):
         for i in range(256):
             test_map[palette.getcolor((i, i, i))] = i
 
-        self.assertEqual(len(test_map), 256)
-        self.assertRaises(ValueError, palette.getcolor, (1, 2, 3))
+        assert len(test_map) == 256
+        with pytest.raises(ValueError):
+            palette.getcolor((1, 2, 3))
 
         # Test unknown color specifier
-        self.assertRaises(ValueError, palette.getcolor, "unknown")
+        with pytest.raises(ValueError):
+            palette.getcolor("unknown")
 
     def test_file(self):
 
@@ -36,12 +38,12 @@ class TestImagePalette(PillowTestCase):
         p = ImagePalette.load(f)
 
         # load returns raw palette information
-        self.assertEqual(len(p[0]), 768)
-        self.assertEqual(p[1], "RGB")
+        assert len(p[0]) == 768
+        assert p[1] == "RGB"
 
         p = ImagePalette.raw(p[1], p[0])
-        self.assertIsInstance(p, ImagePalette.ImagePalette)
-        self.assertEqual(p.palette, palette.tobytes())
+        assert isinstance(p, ImagePalette.ImagePalette)
+        assert p.palette == palette.tobytes()
 
     def test_make_linear_lut(self):
         # Arrange
@@ -52,11 +54,11 @@ class TestImagePalette(PillowTestCase):
         lut = ImagePalette.make_linear_lut(black, white)
 
         # Assert
-        self.assertIsInstance(lut, list)
-        self.assertEqual(len(lut), 256)
+        assert isinstance(lut, list)
+        assert len(lut) == 256
         # Check values
         for i in range(0, len(lut)):
-            self.assertEqual(lut[i], i)
+            assert lut[i] == i
 
     def test_make_linear_lut_not_yet_implemented(self):
         # Update after FIXME
@@ -65,9 +67,8 @@ class TestImagePalette(PillowTestCase):
         white = 255
 
         # Act
-        self.assertRaises(
-            NotImplementedError, ImagePalette.make_linear_lut, black, white
-        )
+        with pytest.raises(NotImplementedError):
+            ImagePalette.make_linear_lut(black, white)
 
     def test_make_gamma_lut(self):
         # Arrange
@@ -77,24 +78,27 @@ class TestImagePalette(PillowTestCase):
         lut = ImagePalette.make_gamma_lut(exp)
 
         # Assert
-        self.assertIsInstance(lut, list)
-        self.assertEqual(len(lut), 256)
+        assert isinstance(lut, list)
+        assert len(lut) == 256
         # Check a few values
-        self.assertEqual(lut[0], 0)
-        self.assertEqual(lut[63], 0)
-        self.assertEqual(lut[127], 8)
-        self.assertEqual(lut[191], 60)
-        self.assertEqual(lut[255], 255)
+        assert lut[0] == 0
+        assert lut[63] == 0
+        assert lut[127] == 8
+        assert lut[191] == 60
+        assert lut[255] == 255
 
     def test_rawmode_valueerrors(self):
         # Arrange
         palette = ImagePalette.raw("RGB", list(range(256)) * 3)
 
         # Act / Assert
-        self.assertRaises(ValueError, palette.tobytes)
-        self.assertRaises(ValueError, palette.getcolor, (1, 2, 3))
+        with pytest.raises(ValueError):
+            palette.tobytes()
+        with pytest.raises(ValueError):
+            palette.getcolor((1, 2, 3))
         f = self.tempfile("temp.lut")
-        self.assertRaises(ValueError, palette.save, f)
+        with pytest.raises(ValueError):
+            palette.save(f)
 
     def test_getdata(self):
         # Arrange
@@ -105,7 +109,7 @@ class TestImagePalette(PillowTestCase):
         mode, data_out = palette.getdata()
 
         # Assert
-        self.assertEqual(mode, "RGB;L")
+        assert mode == "RGB;L"
 
     def test_rawmode_getdata(self):
         # Arrange
@@ -116,8 +120,8 @@ class TestImagePalette(PillowTestCase):
         rawmode, data_out = palette.getdata()
 
         # Assert
-        self.assertEqual(rawmode, "RGB")
-        self.assertEqual(data_in, data_out)
+        assert rawmode == "RGB"
+        assert data_in == data_out
 
     def test_2bit_palette(self):
         # issue #2258, 2 bit palettes are corrupted.
@@ -132,4 +136,5 @@ class TestImagePalette(PillowTestCase):
             assert_image_equal(img, reloaded)
 
     def test_invalid_palette(self):
-        self.assertRaises(IOError, ImagePalette.load, "Tests/images/hopper.jpg")
+        with pytest.raises(IOError):
+            ImagePalette.load("Tests/images/hopper.jpg")

Tests/test_imagepath.py

@@ -1,6 +1,7 @@
 import array
 import struct
 
+import pytest
 from PIL import Image, ImagePath
 
 from .helper import PillowTestCase
@@ -12,62 +13,62 @@ class TestImagePath(PillowTestCase):
         p = ImagePath.Path(list(range(10)))
 
         # sequence interface
-        self.assertEqual(len(p), 5)
-        self.assertEqual(p[0], (0.0, 1.0))
-        self.assertEqual(p[-1], (8.0, 9.0))
-        self.assertEqual(list(p[:1]), [(0.0, 1.0)])
-        with self.assertRaises(TypeError) as cm:
+        assert len(p) == 5
+        assert p[0] == (0.0, 1.0)
+        assert p[-1] == (8.0, 9.0)
+        assert list(p[:1]) == [(0.0, 1.0)]
+        with pytest.raises(TypeError) as cm:
             p["foo"]
-        self.assertEqual(str(cm.exception), "Path indices must be integers, not str")
-        self.assertEqual(
-            list(p), [(0.0, 1.0), (2.0, 3.0), (4.0, 5.0), (6.0, 7.0), (8.0, 9.0)]
-        )
+        assert str(cm.value) == "Path indices must be integers, not str"
+        assert list(p) == [(0.0, 1.0), (2.0, 3.0), (4.0, 5.0), (6.0, 7.0), (8.0, 9.0)]
 
         # method sanity check
-        self.assertEqual(
-            p.tolist(), [(0.0, 1.0), (2.0, 3.0), (4.0, 5.0), (6.0, 7.0), (8.0, 9.0)]
-        )
-        self.assertEqual(
-            p.tolist(1), [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]
-        )
+        assert p.tolist() == [
+            (0.0, 1.0),
+            (2.0, 3.0),
+            (4.0, 5.0),
+            (6.0, 7.0),
+            (8.0, 9.0),
+        ]
+        assert p.tolist(1) == [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]
 
-        self.assertEqual(p.getbbox(), (0.0, 1.0, 8.0, 9.0))
+        assert p.getbbox() == (0.0, 1.0, 8.0, 9.0)
 
-        self.assertEqual(p.compact(5), 2)
-        self.assertEqual(list(p), [(0.0, 1.0), (4.0, 5.0), (8.0, 9.0)])
+        assert p.compact(5) == 2
+        assert list(p) == [(0.0, 1.0), (4.0, 5.0), (8.0, 9.0)]
 
         p.transform((1, 0, 1, 0, 1, 1))
-        self.assertEqual(list(p), [(1.0, 2.0), (5.0, 6.0), (9.0, 10.0)])
+        assert list(p) == [(1.0, 2.0), (5.0, 6.0), (9.0, 10.0)]
 
         # alternative constructors
         p = ImagePath.Path([0, 1])
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path([0.0, 1.0])
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path([0, 1])
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path([(0, 1)])
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path(p)
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path(p.tolist(0))
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path(p.tolist(1))
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
         p = ImagePath.Path(array.array("f", [0, 1]))
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
 
         arr = array.array("f", [0, 1])
         if hasattr(arr, "tobytes"):
             p = ImagePath.Path(arr.tobytes())
         else:
             p = ImagePath.Path(arr.tostring())
-        self.assertEqual(list(p), [(0.0, 1.0)])
+        assert list(p) == [(0.0, 1.0)]
 
     def test_overflow_segfault(self):
         # Some Pythons fail getting the argument as an integer, and it falls
         # through to the sequence. Seeing this on 32-bit Windows.
-        with self.assertRaises((TypeError, MemoryError)):
+        with pytest.raises((TypeError, MemoryError)):
             # post patch, this fails with a memory error
             x = evil()
 

Tests/test_imageqt.py

@@ -52,14 +52,14 @@ class TestImageQt(PillowQtTestCase, PillowTestCase):
         elif ImageQt.qt_version == "side2":
             from PySide2.QtGui import qRgb
 
-        self.assertEqual(qRgb(0, 0, 0), qRgba(0, 0, 0, 255))
+        assert qRgb(0, 0, 0) == qRgba(0, 0, 0, 255)
 
         def checkrgb(r, g, b):
             val = ImageQt.rgb(r, g, b)
             val = val % 2 ** 24  # drop the alpha
-            self.assertEqual(val >> 16, r)
-            self.assertEqual(((val >> 8) % 2 ** 8), g)
-            self.assertEqual(val % 2 ** 8, b)
+            assert val >> 16 == r
+            assert ((val >> 8) % 2 ** 8) == g
+            assert val % 2 ** 8 == b
 
         checkrgb(0, 0, 0)
         checkrgb(255, 0, 0)

Tests/test_imagesequence.py

@@ -1,3 +1,4 @@
+import pytest
 from PIL import Image, ImageSequence, TiffImagePlugin
 
 from .helper import PillowTestCase, assert_image_equal, hopper, skip_unless_feature
@@ -16,32 +17,35 @@ class TestImageSequence(PillowTestCase):
         index = 0
         for frame in seq:
             assert_image_equal(im, frame)
-            self.assertEqual(im.tell(), index)
+            assert im.tell() == index
             index += 1
 
-        self.assertEqual(index, 1)
+        assert index == 1
 
-        self.assertRaises(AttributeError, ImageSequence.Iterator, 0)
+        with pytest.raises(AttributeError):
+            ImageSequence.Iterator(0)
 
     def test_iterator(self):
         with Image.open("Tests/images/multipage.tiff") as im:
             i = ImageSequence.Iterator(im)
             for index in range(0, im.n_frames):
-                self.assertEqual(i[index], next(i))
-            self.assertRaises(IndexError, lambda: i[index + 1])
-            self.assertRaises(StopIteration, next, i)
+                assert i[index] == next(i)
+            with pytest.raises(IndexError):
+                i[index + 1]
+            with pytest.raises(StopIteration):
+                next(i)
 
     def test_iterator_min_frame(self):
         with Image.open("Tests/images/hopper.psd") as im:
             i = ImageSequence.Iterator(im)
             for index in range(1, im.n_frames):
-                self.assertEqual(i[index], next(i))
+                assert i[index] == next(i)
 
     def _test_multipage_tiff(self):
         with Image.open("Tests/images/multipage.tiff") as im:
             for index, frame in enumerate(ImageSequence.Iterator(im)):
                 frame.load()
-                self.assertEqual(index, im.tell())
+                assert index == im.tell()
                 frame.convert("RGB")
 
     def test_tiff(self):
@@ -69,23 +73,23 @@ class TestImageSequence(PillowTestCase):
             color1 = im.getpalette()[0:3]
             im.seek(0)
             color2 = im.getpalette()[0:3]
-            self.assertEqual(color1, color2)
+            assert color1 == color2
 
     def test_all_frames(self):
         # Test a single image
         with Image.open("Tests/images/iss634.gif") as im:
             ims = ImageSequence.all_frames(im)
 
-            self.assertEqual(len(ims), 42)
+            assert len(ims) == 42
             for i, im_frame in enumerate(ims):
-                self.assertFalse(im_frame is im)
+                assert im_frame is not im
 
                 im.seek(i)
                 assert_image_equal(im, im_frame)
 
             # Test a series of images
             ims = ImageSequence.all_frames([im, hopper(), im])
-            self.assertEqual(len(ims), 85)
+            assert len(ims) == 85
 
             # Test an operation
             ims = ImageSequence.all_frames(im, lambda im_frame: im_frame.rotate(90))

Tests/test_imagewin.py

@@ -18,7 +18,7 @@ class TestImageWin(PillowTestCase):
         dc2 = int(hdc)
 
         # Assert
-        self.assertEqual(dc2, 50)
+        assert dc2 == 50
 
     def test_hwnd(self):
         # Arrange
@@ -29,7 +29,7 @@ class TestImageWin(PillowTestCase):
         wnd2 = int(hwnd)
 
         # Assert
-        self.assertEqual(wnd2, 50)
+        assert wnd2 == 50
 
 
 @unittest.skipUnless(is_win32(), "Windows only")
@@ -42,7 +42,7 @@ class TestImageWinDib(PillowTestCase):
         dib = ImageWin.Dib(im)
 
         # Assert
-        self.assertEqual(dib.size, im.size)
+        assert dib.size == im.size
 
     def test_dib_mode_string(self):
         # Arrange
@@ -53,7 +53,7 @@ class TestImageWinDib(PillowTestCase):
         dib = ImageWin.Dib(mode, size)
 
         # Assert
-        self.assertEqual(dib.size, (128, 128))
+        assert dib.size == (128, 128)
 
     def test_dib_paste(self):
         # Arrange
@@ -67,7 +67,7 @@ class TestImageWinDib(PillowTestCase):
         dib.paste(im)
 
         # Assert
-        self.assertEqual(dib.size, (128, 128))
+        assert dib.size == (128, 128)
 
     def test_dib_paste_bbox(self):
         # Arrange
@@ -82,7 +82,7 @@ class TestImageWinDib(PillowTestCase):
         dib.paste(im, bbox)
 
         # Assert
-        self.assertEqual(dib.size, (128, 128))
+        assert dib.size == (128, 128)
 
     def test_dib_frombytes_tobytes_roundtrip(self):
         # Arrange
@@ -95,7 +95,7 @@ class TestImageWinDib(PillowTestCase):
         dib2 = ImageWin.Dib(mode, size)
 
         # Confirm they're different
-        self.assertNotEqual(dib1.tobytes(), dib2.tobytes())
+        assert dib1.tobytes() != dib2.tobytes()
 
         # Act
         # Make one the same as the using tobytes()/frombytes()
@@ -104,4 +104,4 @@ class TestImageWinDib(PillowTestCase):
 
         # Assert
         # Confirm they're the same
-        self.assertEqual(dib1.tobytes(), dib2.tobytes())
+        assert dib1.tobytes() == dib2.tobytes()

Tests/test_lib_pack.py

@@ -1,5 +1,6 @@
 import sys
 
+import pytest
 from PIL import Image
 
 from .helper import PillowTestCase
@@ -20,7 +21,7 @@ class TestLibPack(PillowTestCase):
             data_len = data * len(pixels)
             data = bytes(range(1, data_len + 1))
 
-        self.assertEqual(data, im.tobytes("raw", rawmode))
+        assert data == im.tobytes("raw", rawmode)
 
     def test_1(self):
         self.assert_pack("1", "1", b"\x01", 0, 0, 0, 0, 0, 0, 0, X)
@@ -234,7 +235,7 @@ class TestLibUnpack(PillowTestCase):
         im = Image.frombytes(mode, (len(pixels), 1), data, "raw", rawmode, 0, 1)
 
         for x, pixel in enumerate(pixels):
-            self.assertEqual(pixel, im.getpixel((x, 0)))
+            assert pixel == im.getpixel((x, 0))
 
     def test_1(self):
         self.assert_unpack("1", "1", b"\x01", 0, 0, 0, 0, 0, 0, 0, X)
@@ -719,6 +720,9 @@ class TestLibUnpack(PillowTestCase):
             self.assert_unpack("CMYK", "CMYK;16N", 8, (1, 3, 5, 7), (9, 11, 13, 15))
 
     def test_value_error(self):
-        self.assertRaises(ValueError, self.assert_unpack, "L", "L", 0, 0)
-        self.assertRaises(ValueError, self.assert_unpack, "RGB", "RGB", 2, 0)
-        self.assertRaises(ValueError, self.assert_unpack, "CMYK", "CMYK", 2, 0)
+        with pytest.raises(ValueError):
+            self.assert_unpack("L", "L", 0, 0)
+        with pytest.raises(ValueError):
+            self.assert_unpack("RGB", "RGB", 2, 0)
+        with pytest.raises(ValueError):
+            self.assert_unpack("CMYK", "CMYK", 2, 0)

Tests/test_mode_i16.py

@@ -9,7 +9,7 @@ class TestModeI16(PillowTestCase):
 
     def verify(self, im1):
         im2 = self.original.copy()
-        self.assertEqual(im1.size, im2.size)
+        assert im1.size == im2.size
         pix1 = im1.load()
         pix2 = im2.load()
         for y in range(im1.size[1]):
@@ -17,14 +17,8 @@ class TestModeI16(PillowTestCase):
                 xy = x, y
                 p1 = pix1[xy]
                 p2 = pix2[xy]
-                self.assertEqual(
-                    p1,
-                    p2,
-                    (
-                        "got {!r} from mode {} at {}, expected {!r}".format(
-                            p1, im1.mode, xy, p2
-                        )
-                    ),
+                assert p1 == p2, "got {!r} from mode {} at {}, expected {!r}".format(
+                    p1, im1.mode, xy, p2
                 )
 
     def test_basic(self):
@@ -63,10 +57,10 @@ class TestModeI16(PillowTestCase):
             self.verify(imOut)
 
             imIn = Image.new(mode, (1, 1), 1)
-            self.assertEqual(imIn.getpixel((0, 0)), 1)
+            assert imIn.getpixel((0, 0)) == 1
 
             imIn.putpixel((0, 0), 2)
-            self.assertEqual(imIn.getpixel((0, 0)), 2)
+            assert imIn.getpixel((0, 0)) == 2
 
             if mode == "L":
                 maximum = 255
@@ -74,10 +68,10 @@ class TestModeI16(PillowTestCase):
                 maximum = 32767
 
             imIn = Image.new(mode, (1, 1), 256)
-            self.assertEqual(imIn.getpixel((0, 0)), min(256, maximum))
+            assert imIn.getpixel((0, 0)) == min(256, maximum)
 
             imIn.putpixel((0, 0), 512)
-            self.assertEqual(imIn.getpixel((0, 0)), min(512, maximum))
+            assert imIn.getpixel((0, 0)) == min(512, maximum)
 
         basic("L")
 
@@ -93,10 +87,10 @@ class TestModeI16(PillowTestCase):
 
         order = 1 if Image._ENDIAN == "<" else -1
 
-        self.assertEqual(tobytes("L"), b"\x01")
-        self.assertEqual(tobytes("I;16"), b"\x01\x00")
-        self.assertEqual(tobytes("I;16B"), b"\x00\x01")
-        self.assertEqual(tobytes("I"), b"\x01\x00\x00\x00"[::order])
+        assert tobytes("L") == b"\x01"
+        assert tobytes("I;16") == b"\x01\x00"
+        assert tobytes("I;16B") == b"\x00\x01"
+        assert tobytes("I") == b"\x01\x00\x00\x00"[::order]
 
     def test_convert(self):
 

Tests/test_pickle.py

@@ -20,7 +20,7 @@ class TestPickle(PillowTestCase):
                 loaded_im = pickle.load(f)
 
             # Assert
-            self.assertEqual(im, loaded_im)
+            assert im == loaded_im
 
     def helper_pickle_string(
         self, pickle, protocol=0, test_file="Tests/images/hopper.jpg", mode=None
@@ -34,7 +34,7 @@ class TestPickle(PillowTestCase):
             loaded_im = pickle.loads(dumped_string)
 
             # Assert
-            self.assertEqual(im, loaded_im)
+            assert im == loaded_im
 
     def test_pickle_image(self):
         # Act / Assert
@@ -86,4 +86,4 @@ class TestPickle(PillowTestCase):
                 loaded_im = pickle.load(f)
 
             im.mode = "PA"
-            self.assertEqual(im, loaded_im)
+            assert im == loaded_im

Tests/test_qt_image_toqimage.py

@@ -20,8 +20,8 @@ class TestToQImage(PillowQtTestCase, PillowTestCase):
             src = hopper(mode)
             data = ImageQt.toqimage(src)
 
-            self.assertIsInstance(data, QImage)
-            self.assertFalse(data.isNull())
+            assert isinstance(data, QImage)
+            assert not data.isNull()
 
             # reload directly from the qimage
             rt = ImageQt.fromqimage(data)

Tests/test_qt_image_toqpixmap.py

@@ -12,8 +12,8 @@ class TestToQPixmap(PillowQPixmapTestCase, PillowTestCase):
         for mode in ("1", "RGB", "RGBA", "L", "P"):
             data = ImageQt.toqpixmap(hopper(mode))
 
-            self.assertIsInstance(data, QPixmap)
-            self.assertFalse(data.isNull())
+            assert isinstance(data, QPixmap)
+            assert not data.isNull()
 
             # Test saving the file
             tempfile = self.tempfile("temp_{}.png".format(mode))

Tests/test_tiff_ifdrational.py

@@ -11,8 +11,8 @@ class Test_IFDRational(PillowTestCase):
 
         t = IFDRational(num, denom)
 
-        self.assertEqual(target, t)
-        self.assertEqual(t, target)
+        assert target == t
+        assert t == target
 
     def test_sanity(self):
 
@@ -33,13 +33,13 @@ class Test_IFDRational(PillowTestCase):
 
         xres = IFDRational(72)
         yres = IFDRational(72)
-        self.assertIsNotNone(xres._val)
-        self.assertIsNotNone(xres.numerator)
-        self.assertIsNotNone(xres.denominator)
-        self.assertIsNotNone(yres._val)
+        assert xres._val is not None
+        assert xres.numerator is not None
+        assert xres.denominator is not None
+        assert yres._val is not None
 
-        self.assertTrue(xres and 1)
-        self.assertTrue(xres and yres)
+        assert xres and 1
+        assert xres and yres
 
     def test_ifd_rational_save(self):
         methods = (True, False)
@@ -55,6 +55,4 @@ class Test_IFDRational(PillowTestCase):
             im.save(out, dpi=(res, res), compression="raw")
 
             with Image.open(out) as reloaded:
-                self.assertEqual(
-                    float(IFDRational(301, 1)), float(reloaded.tag_v2[282])
-                )
+                assert float(IFDRational(301, 1)) == float(reloaded.tag_v2[282])