Merge branch 'main' into jpeg-app-segments

.coveragerc

@@ -12,6 +12,9 @@ exclude_also =
     except ImportError
     if TYPE_CHECKING:
     @abc.abstractmethod
+    # Empty bodies in protocols or abstract methods
+    ^\s*def [a-zA-Z0-9_]+\(.*\)(\s*->.*)?:\s*\.\.\.(\s*#.*)?$
+    ^\s*\.\.\.(\s*#.*)?$
 
 [run]
 omit =

Tests/helper.py

@@ -244,7 +244,7 @@ def fromstring(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def tostring(im: Image.Image, string_format: str, **options: dict[str, Any]) -> bytes:
+def tostring(im: Image.Image, string_format: str, **options: Any) -> bytes:
     out = BytesIO()
     im.save(out, string_format, **options)
     return out.getvalue()

Tests/test_color_lut.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from array import array
+from types import ModuleType
 
 import pytest
 
@@ -8,6 +9,7 @@ from PIL import Image, ImageFilter
 
 from .helper import assert_image_equal
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -397,6 +399,7 @@ class TestColorLut3DFilter:
 
     @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
     def test_numpy_sources(self) -> None:
+        assert numpy is not None
         table = numpy.ones((5, 6, 7, 3), dtype=numpy.float16)
         with pytest.raises(ValueError, match="should have either channels"):
             lut = ImageFilter.Color3DLUT((5, 6, 7), table)
@@ -430,6 +433,7 @@ class TestColorLut3DFilter:
 
     @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
     def test_numpy_formats(self) -> None:
+        assert numpy is not None
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",

Tests/test_core_resources.py

@@ -187,6 +187,6 @@ class TestEnvVars:
             {"PILLOW_BLOCKS_MAX": "wat"},
         ),
     )
-    def test_warnings(self, var) -> None:
+    def test_warnings(self, var: dict[str, str]) -> None:
         with pytest.warns(UserWarning):
             Image._apply_env_variables(var)

Tests/test_file_dds.py

@@ -48,7 +48,7 @@ TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA = "Tests/images/uncompressed_rgb.dds"
         TEST_FILE_DX10_BC1_TYPELESS,
     ),
 )
-def test_sanity_dxt1_bc1(image_path) -> None:
+def test_sanity_dxt1_bc1(image_path: str) -> None:
     """Check DXT1 and BC1 images can be opened"""
     with Image.open(TEST_FILE_DXT1.replace(".dds", ".png")) as target:
         target = target.convert("RGBA")
@@ -96,7 +96,7 @@ def test_sanity_dxt5() -> None:
         TEST_FILE_BC4U,
     ),
 )
-def test_sanity_ati1_bc4u(image_path) -> None:
+def test_sanity_ati1_bc4u(image_path: str) -> None:
     """Check ATI1 and BC4U images can be opened"""
 
     with Image.open(image_path) as im:
@@ -117,7 +117,7 @@ def test_sanity_ati1_bc4u(image_path) -> None:
         TEST_FILE_DX10_BC4_TYPELESS,
     ),
 )
-def test_dx10_bc4(image_path) -> None:
+def test_dx10_bc4(image_path: str) -> None:
     """Check DX10 BC4 images can be opened"""
 
     with Image.open(image_path) as im:
@@ -138,7 +138,7 @@ def test_dx10_bc4(image_path) -> None:
         TEST_FILE_BC5U,
     ),
 )
-def test_sanity_ati2_bc5u(image_path) -> None:
+def test_sanity_ati2_bc5u(image_path: str) -> None:
     """Check ATI2 and BC5U images can be opened"""
 
     with Image.open(image_path) as im:
@@ -162,7 +162,7 @@ def test_sanity_ati2_bc5u(image_path) -> None:
         (TEST_FILE_BC5S, TEST_FILE_BC5S),
     ),
 )
-def test_dx10_bc5(image_path, expected_path) -> None:
+def test_dx10_bc5(image_path: str, expected_path: str) -> None:
     """Check DX10 BC5 images can be opened"""
 
     with Image.open(image_path) as im:
@@ -176,7 +176,7 @@ def test_dx10_bc5(image_path, expected_path) -> None:
 
 
 @pytest.mark.parametrize("image_path", (TEST_FILE_BC6H, TEST_FILE_BC6HS))
-def test_dx10_bc6h(image_path) -> None:
+def test_dx10_bc6h(image_path: str) -> None:
     """Check DX10 BC6H/BC6HS images can be opened"""
 
     with Image.open(image_path) as im:
@@ -257,7 +257,7 @@ def test_dx10_r8g8b8a8_unorm_srgb() -> None:
         ("RGBA", (800, 600), TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA),
     ],
 )
-def test_uncompressed(mode, size, test_file) -> None:
+def test_uncompressed(mode: str, size: tuple[int, int], test_file: str) -> None:
     """Check uncompressed images can be opened"""
 
     with Image.open(test_file) as im:
@@ -359,7 +359,7 @@ def test_unsupported_bitcount() -> None:
         "Tests/images/unimplemented_pfflags.dds",
     ),
 )
-def test_not_implemented(test_file) -> None:
+def test_not_implemented(test_file: str) -> None:
     with pytest.raises(NotImplementedError):
         with Image.open(test_file):
             pass
@@ -381,7 +381,7 @@ def test_save_unsupported_mode(tmp_path: Path) -> None:
         ("RGBA", "Tests/images/pil123rgba.png"),
     ],
 )
-def test_save(mode, test_file, tmp_path: Path) -> None:
+def test_save(mode: str, test_file: str, tmp_path: Path) -> None:
     out = str(tmp_path / "temp.dds")
     with Image.open(test_file) as im:
         assert im.mode == mode

Tests/test_file_fli.py

@@ -147,7 +147,7 @@ def test_seek() -> None:
     ],
 )
 @pytest.mark.timeout(timeout=3)
-def test_timeouts(test_file) -> None:
+def test_timeouts(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):
@@ -160,7 +160,7 @@ def test_timeouts(test_file) -> None:
         "Tests/images/crash-5762152299364352.fli",
     ],
 )
-def test_crash(test_file) -> None:
+def test_crash(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):

Tests/test_file_gribstub.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
+from typing import IO
 
 import pytest
 
@@ -55,15 +56,15 @@ def test_handler(tmp_path: Path) -> None:
         loaded = False
         saved = False
 
-        def open(self, im) -> None:
+        def open(self, im: Image.Image) -> None:
             self.opened = True
 
-        def load(self, im):
+        def load(self, im: Image.Image) -> Image.Image:
             self.loaded = True
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
-        def save(self, im, fp, filename) -> None:
+        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
     handler = TestHandler()

Tests/test_file_hdf5stub.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
+from typing import IO
 
 import pytest
 
@@ -56,15 +57,15 @@ def test_handler(tmp_path: Path) -> None:
         loaded = False
         saved = False
 
-        def open(self, im) -> None:
+        def open(self, im: Image.Image) -> None:
             self.opened = True
 
-        def load(self, im):
+        def load(self, im: Image.Image) -> Image.Image:
             self.loaded = True
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
-        def save(self, im, fp, filename) -> None:
+        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
     handler = TestHandler()

Tests/test_file_jpeg.py

@@ -5,6 +5,7 @@ import re
 import warnings
 from io import BytesIO
 from pathlib import Path
+from types import ModuleType
 from typing import Any
 
 import pytest
@@ -33,6 +34,7 @@ from .helper import (
     skip_unless_feature,
 )
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
@@ -465,25 +467,25 @@ class TestFileJpeg:
         for subsampling in (-1, 3):  # (default, invalid)
             im = self.roundtrip(hopper(), subsampling=subsampling)
             assert getsampling(im) == (2, 2, 1, 1, 1, 1)
-        for subsampling in (0, "4:4:4"):
+        for subsampling1 in (0, "4:4:4"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (1, 1, 1, 1, 1, 1)
-        for subsampling in (1, "4:2:2"):
+        for subsampling1 in (1, "4:2:2"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (2, 1, 1, 1, 1, 1)
-        for subsampling in (2, "4:2:0", "4:1:1"):
+        for subsampling1 in (2, "4:2:0", "4:1:1"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (2, 2, 1, 1, 1, 1)
 
         # RGB colorspace
-        for subsampling in (-1, 0, "4:4:4"):
+        for subsampling1 in (-1, 0, "4:4:4"):
             # "4:4:4" doesn't really make sense for RGB, but the conversion
             # to an integer happens at a higher level
-            im = self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling)
+            im = self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling1)
             assert getsampling(im) == (1, 1, 1, 1, 1, 1)
-        for subsampling in (1, "4:2:2", 2, "4:2:0", 3):
+        for subsampling1 in (1, "4:2:2", 2, "4:2:0", 3):
             with pytest.raises(OSError):
-                self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling)
+                self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling1)
 
         with pytest.raises(TypeError):
             self.roundtrip(hopper(), subsampling="1:1:1")

Tests/test_file_palm.py

@@ -11,7 +11,7 @@ from PIL import Image
 from .helper import assert_image_equal, hopper, magick_command
 
 
-def helper_save_as_palm(tmp_path: Path, mode) -> None:
+def helper_save_as_palm(tmp_path: Path, mode: str) -> None:
     # Arrange
     im = hopper(mode)
     outfile = str(tmp_path / ("temp_" + mode + ".palm"))
@@ -24,7 +24,7 @@ def helper_save_as_palm(tmp_path: Path, mode) -> None:
     assert os.path.getsize(outfile) > 0
 
 
-def open_with_magick(magick, tmp_path: Path, f):
+def open_with_magick(magick: list[str], tmp_path: Path, f: str) -> Image.Image:
     outfile = str(tmp_path / "temp.png")
     rc = subprocess.call(
         magick + [f, outfile], stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT
@@ -33,7 +33,7 @@ def open_with_magick(magick, tmp_path: Path, f):
     return Image.open(outfile)
 
 
-def roundtrip(tmp_path: Path, mode) -> None:
+def roundtrip(tmp_path: Path, mode: str) -> None:
     magick = magick_command()
     if not magick:
         return
@@ -66,6 +66,6 @@ def test_p_mode(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "RGB"))
-def test_oserror(tmp_path: Path, mode) -> None:
+def test_oserror(tmp_path: Path, mode: str) -> None:
     with pytest.raises(OSError):
         helper_save_as_palm(tmp_path, mode)

Tests/test_file_tar.py

@@ -19,7 +19,7 @@ TEST_TAR_FILE = "Tests/images/hopper.tar"
         ("jpg", "hopper.jpg", "JPEG"),
     ),
 )
-def test_sanity(codec, test_path, format) -> None:
+def test_sanity(codec: str, test_path: str, format: str) -> None:
     if features.check(codec):
         with TarIO.TarIO(TEST_TAR_FILE, test_path) as tar:
             with Image.open(tar) as im:

Tests/test_file_webp_metadata.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from io import BytesIO
 from pathlib import Path
+from types import ModuleType
 
 import pytest
 
@@ -14,6 +15,7 @@ pytestmark = [
     skip_unless_feature("webp_mux"),
 ]
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:

Tests/test_image.py

@@ -8,6 +8,7 @@ import sys
 import tempfile
 import warnings
 from pathlib import Path
+from typing import IO
 
 import pytest
 
@@ -61,11 +62,11 @@ class TestImage:
             "HSV",
         ),
     )
-    def test_image_modes_success(self, mode) -> None:
+    def test_image_modes_success(self, mode: str) -> None:
         Image.new(mode, (1, 1))
 
     @pytest.mark.parametrize("mode", ("", "bad", "very very long"))
-    def test_image_modes_fail(self, mode) -> None:
+    def test_image_modes_fail(self, mode: str) -> None:
         with pytest.raises(ValueError) as e:
             Image.new(mode, (1, 1))
         assert str(e.value) == "unrecognized image mode"
@@ -100,7 +101,7 @@ class TestImage:
 
     def test_repr_pretty(self) -> None:
         class Pretty:
-            def text(self, text) -> None:
+            def text(self, text: str) -> None:
                 self.pretty_output = text
 
         im = Image.new("L", (100, 100))
@@ -162,8 +163,6 @@ class TestImage:
                 pass
 
     def test_pathlib(self, tmp_path: Path) -> None:
-        from PIL.Image import Path
-
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
             assert im.mode == "P"
             assert im.size == (10, 10)
@@ -184,7 +183,9 @@ class TestImage:
         temp_file = str(tmp_path / "temp.jpg")
 
         class FP:
-            def write(self, b) -> None:
+            name: str
+
+            def write(self, b: bytes) -> None:
                 pass
 
         fp = FP()
@@ -538,7 +539,7 @@ class TestImage:
         "PILLOW_VALGRIND_TEST" in os.environ, reason="Valgrind is slower"
     )
     @pytest.mark.parametrize("size", ((0, 100000000), (100000000, 0)))
-    def test_empty_image(self, size) -> None:
+    def test_empty_image(self, size: tuple[int, int]) -> None:
         Image.new("RGB", size)
 
     def test_storage_neg(self) -> None:
@@ -565,7 +566,7 @@ class TestImage:
             Image.linear_gradient(wrong_mode)
 
     @pytest.mark.parametrize("mode", ("L", "P", "I", "F"))
-    def test_linear_gradient(self, mode) -> None:
+    def test_linear_gradient(self, mode: str) -> None:
         # Arrange
         target_file = "Tests/images/linear_gradient.png"
 
@@ -590,7 +591,7 @@ class TestImage:
             Image.radial_gradient(wrong_mode)
 
     @pytest.mark.parametrize("mode", ("L", "P", "I", "F"))
-    def test_radial_gradient(self, mode) -> None:
+    def test_radial_gradient(self, mode: str) -> None:
         # Arrange
         target_file = "Tests/images/radial_gradient.png"
 
@@ -665,7 +666,11 @@ class TestImage:
         blank_p.palette = None
         blank_pa.palette = None
 
-        def _make_new(base_image, image, palette_result=None) -> None:
+        def _make_new(
+            base_image: Image.Image,
+            image: Image.Image,
+            palette_result: ImagePalette.ImagePalette | None = None,
+        ) -> None:
             new_image = base_image._new(image.im)
             assert new_image.mode == image.mode
             assert new_image.size == image.size
@@ -713,7 +718,7 @@ class TestImage:
     def test_load_on_nonexclusive_multiframe(self) -> None:
         with open("Tests/images/frozenpond.mpo", "rb") as fp:
 
-            def act(fp) -> None:
+            def act(fp: IO[bytes]) -> None:
                 im = Image.open(fp)
                 im.load()
 
@@ -906,12 +911,12 @@ class TestImage:
                 assert exif.get_ifd(0xA005)
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero_tobytes(self, size) -> None:
+    def test_zero_tobytes(self, size: tuple[int, int]) -> None:
         im = Image.new("RGB", size)
         assert im.tobytes() == b""
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero_frombytes(self, size) -> None:
+    def test_zero_frombytes(self, size: tuple[int, int]) -> None:
         Image.frombytes("RGB", size, b"")
 
         im = Image.new("RGB", size)
@@ -996,7 +1001,7 @@ class TestImage:
             "01r_00.pcx",
         ],
     )
-    def test_overrun(self, path) -> None:
+    def test_overrun(self, path: str) -> None:
         """For overrun completeness, test as:
         valgrind pytest -qq Tests/test_image.py::TestImage::test_overrun | grep decode.c
         """
@@ -1023,7 +1028,7 @@ class TestImage:
             pass
         assert not hasattr(im, "fp")
 
-    def test_close_graceful(self, caplog) -> None:
+    def test_close_graceful(self, caplog: pytest.LogCaptureFixture) -> None:
         with Image.open("Tests/images/hopper.jpg") as im:
             copy = im.copy()
             with caplog.at_level(logging.DEBUG):
@@ -1034,10 +1039,10 @@ class TestImage:
 
 
 class MockEncoder:
-    pass
+    args: tuple[str, ...]
 
 
-def mock_encode(*args):
+def mock_encode(*args: str) -> MockEncoder:
     encoder = MockEncoder()
     encoder.args = args
     return encoder

Tests/test_image_access.py

@@ -4,6 +4,7 @@ import os
 import subprocess
 import sys
 import sysconfig
+from types import ModuleType
 
 import pytest
 
@@ -23,6 +24,7 @@ else:
     except ImportError:
         cffi = None
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -71,9 +73,10 @@ class TestImagePutPixel(AccessTest):
         pix1 = im1.load()
         pix2 = im2.load()
 
-        for x, y in ((0, "0"), ("0", 0)):
+        with pytest.raises(TypeError):
-            with pytest.raises(TypeError):
+            pix1[0, "0"]
-                pix1[x, y]
+        with pytest.raises(TypeError):
+            pix1["0", 0]
 
         for y in range(im1.size[1]):
             for x in range(im1.size[0]):
@@ -123,12 +126,13 @@ class TestImagePutPixel(AccessTest):
         im = hopper()
         pix = im.load()
 
+        assert numpy is not None
         assert pix[numpy.int32(1), numpy.int32(2)] == (18, 20, 59)
 
 
 class TestImageGetPixel(AccessTest):
     @staticmethod
-    def color(mode):
+    def color(mode: str) -> int | tuple[int, ...]:
         bands = Image.getmodebands(mode)
         if bands == 1:
             return 1
@@ -138,12 +142,13 @@ class TestImageGetPixel(AccessTest):
             return (16, 32, 49)
         return tuple(range(1, bands + 1))
 
-    def check(self, mode, expected_color=None) -> None:
+    def check(self, mode: str, expected_color_int: int | None = None) -> None:
         if self._need_cffi_access and mode.startswith("BGR;"):
             pytest.skip("Support not added to deprecated module for BGR;* modes")
 
-        if not expected_color:
+        expected_color = (
-            expected_color = self.color(mode)
+            self.color(mode) if expected_color_int is None else expected_color_int
+        )
 
         # check putpixel
         im = Image.new(mode, (1, 1), None)
@@ -222,7 +227,7 @@ class TestImageGetPixel(AccessTest):
             "YCbCr",
         ),
     )
-    def test_basic(self, mode) -> None:
+    def test_basic(self, mode: str) -> None:
         self.check(mode)
 
     def test_list(self) -> None:
@@ -231,14 +236,14 @@ class TestImageGetPixel(AccessTest):
 
     @pytest.mark.parametrize("mode", ("I;16", "I;16B"))
     @pytest.mark.parametrize("expected_color", (2**15 - 1, 2**15, 2**15 + 1, 2**16 - 1))
-    def test_signedness(self, mode, expected_color) -> None:
+    def test_signedness(self, mode: str, expected_color: int) -> None:
         # see https://github.com/python-pillow/Pillow/issues/452
         # pixelaccess is using signed int* instead of uint*
         self.check(mode, expected_color)
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
     @pytest.mark.parametrize("color", ((255, 0, 0), (255, 0, 0, 255)))
-    def test_p_putpixel_rgb_rgba(self, mode, color) -> None:
+    def test_p_putpixel_rgb_rgba(self, mode: str, color: tuple[int, ...]) -> None:
         im = Image.new(mode, (1, 1))
         im.putpixel((0, 0), color)
 
@@ -262,7 +267,7 @@ class TestCffiGetPixel(TestImageGetPixel):
 class TestCffi(AccessTest):
     _need_cffi_access = True
 
-    def _test_get_access(self, im) -> None:
+    def _test_get_access(self, im: Image.Image) -> None:
         """Do we get the same thing as the old pixel access
 
         Using private interfaces, forcing a capi access and
@@ -299,7 +304,7 @@ class TestCffi(AccessTest):
         # im = Image.new('I;32B', (10, 10), 2**10)
         # self._test_get_access(im)
 
-    def _test_set_access(self, im, color) -> None:
+    def _test_set_access(self, im: Image.Image, color: tuple[int, ...] | float) -> None:
         """Are we writing the correct bits into the image?
 
         Using private interfaces, forcing a capi access and
@@ -359,7 +364,7 @@ class TestCffi(AccessTest):
                 assert px[i, 0] == 0
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
-    def test_p_putpixel_rgb_rgba(self, mode) -> None:
+    def test_p_putpixel_rgb_rgba(self, mode: str) -> None:
         for color in ((255, 0, 0), (255, 0, 0, 127 if mode == "PA" else 255)):
             im = Image.new(mode, (1, 1))
             with pytest.warns(DeprecationWarning):
@@ -377,7 +382,7 @@ class TestImagePutPixelError(AccessTest):
     INVALID_TYPES = ["foo", 1.0, None]
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1)
-    def test_putpixel_type_error1(self, mode) -> None:
+    def test_putpixel_type_error1(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(TypeError, match="color must be int or tuple"):
@@ -400,14 +405,16 @@ class TestImagePutPixelError(AccessTest):
             ),
         ),
     )
-    def test_putpixel_invalid_number_of_bands(self, mode, band_numbers, match) -> None:
+    def test_putpixel_invalid_number_of_bands(
+        self, mode: str, band_numbers: tuple[int, ...], match: str
+    ) -> None:
         im = hopper(mode)
         for band_number in band_numbers:
             with pytest.raises(TypeError, match=match):
                 im.putpixel((0, 0), (0,) * band_number)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES2)
-    def test_putpixel_type_error2(self, mode) -> None:
+    def test_putpixel_type_error2(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(
@@ -416,7 +423,7 @@ class TestImagePutPixelError(AccessTest):
                 im.putpixel((0, 0), v)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1 + IMAGE_MODES2)
-    def test_putpixel_overflow_error(self, mode) -> None:
+    def test_putpixel_overflow_error(self, mode: str) -> None:
         im = hopper(mode)
         with pytest.raises(OverflowError):
             im.putpixel((0, 0), 2**80)
@@ -428,7 +435,7 @@ class TestEmbeddable:
     def test_embeddable(self) -> None:
         import ctypes
 
-        from setuptools.command.build_ext import new_compiler
+        from setuptools.command import build_ext
 
         with open("embed_pil.c", "w", encoding="utf-8") as fh:
             fh.write(
@@ -457,7 +464,7 @@ int main(int argc, char* argv[])
                 % sys.prefix.replace("\\", "\\\\")
             )
 
-        compiler = new_compiler()
+        compiler = getattr(build_ext, "new_compiler")()
         compiler.add_include_dir(sysconfig.get_config_var("INCLUDEPY"))
 
         libdir = sysconfig.get_config_var("LIBDIR") or sysconfig.get_config_var(
@@ -471,7 +478,7 @@ int main(int argc, char* argv[])
         env["PATH"] = sys.prefix + ";" + env["PATH"]
 
         # do not display the Windows Error Reporting dialog
-        ctypes.windll.kernel32.SetErrorMode(0x0002)
+        getattr(ctypes, "windll").kernel32.SetErrorMode(0x0002)
 
         process = subprocess.Popen(["embed_pil.exe"], env=env)
         process.communicate()

Tests/test_image_array.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import Any
+
 import pytest
 from packaging.version import parse as parse_version
 
@@ -13,7 +15,7 @@ im = hopper().resize((128, 100))
 
 
 def test_toarray() -> None:
-    def test(mode):
+    def test(mode: str) -> tuple[tuple[int, ...], str, int]:
         ai = numpy.array(im.convert(mode))
         return ai.shape, ai.dtype.str, ai.nbytes
 
@@ -50,14 +52,14 @@ def test_fromarray() -> None:
     class Wrapper:
         """Class with API matching Image.fromarray"""
 
-        def __init__(self, img, arr_params) -> None:
+        def __init__(self, img: Image.Image, arr_params: dict[str, Any]) -> None:
             self.img = img
             self.__array_interface__ = arr_params
 
-        def tobytes(self):
+        def tobytes(self) -> bytes:
             return self.img.tobytes()
 
-    def test(mode):
+    def test(mode: str) -> tuple[str, tuple[int, int], bool]:
         i = im.convert(mode)
         a = numpy.array(i)
         # Make wrapper instance for image, new array interface

Tests/test_image_draft.py

@@ -7,7 +7,12 @@ from .helper import fromstring, skip_unless_feature, tostring
 pytestmark = skip_unless_feature("jpg")
 
 
-def draft_roundtrip(in_mode, in_size, req_mode, req_size):
+def draft_roundtrip(
+    in_mode: str,
+    in_size: tuple[int, int],
+    req_mode: str | None,
+    req_size: tuple[int, int] | None,
+) -> Image.Image:
     im = Image.new(in_mode, in_size)
     data = tostring(im, "JPEG")
     im = fromstring(data)

Tests/test_image_entropy.py

@@ -4,7 +4,7 @@ from .helper import hopper
 
 
 def test_entropy() -> None:
-    def entropy(mode):
+    def entropy(mode: str) -> float:
         return hopper(mode).entropy()
 
     assert round(abs(entropy("1") - 0.9138803254693582), 7) == 0

Tests/test_image_filter.py

@@ -36,7 +36,7 @@ from .helper import assert_image_equal, hopper
     ),
 )
 @pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
-def test_sanity(filter_to_apply, mode) -> None:
+def test_sanity(filter_to_apply: ImageFilter.Filter, mode: str) -> None:
     im = hopper(mode)
     if mode != "I" or isinstance(filter_to_apply, ImageFilter.BuiltinFilter):
         out = im.filter(filter_to_apply)
@@ -45,7 +45,7 @@ def test_sanity(filter_to_apply, mode) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
-def test_sanity_error(mode) -> None:
+def test_sanity_error(mode: str) -> None:
     with pytest.raises(TypeError):
         im = hopper(mode)
         im.filter("hello")
@@ -53,7 +53,7 @@ def test_sanity_error(mode) -> None:
 
 # crashes on small images
 @pytest.mark.parametrize("size", ((1, 1), (2, 2), (3, 3)))
-def test_crash(size) -> None:
+def test_crash(size: tuple[int, int]) -> None:
     im = Image.new("RGB", size)
     im.filter(ImageFilter.SMOOTH)
 
@@ -67,7 +67,10 @@ def test_crash(size) -> None:
         ("RGB", ((4, 0, 0), (0, 0, 0))),
     ),
 )
-def test_modefilter(mode, expected) -> None:
+def test_modefilter(
+    mode: str,
+    expected: tuple[int, int] | tuple[tuple[int, int, int], tuple[int, int, int]],
+) -> None:
     im = Image.new(mode, (3, 3), None)
     im.putdata(list(range(9)))
     # image is:
@@ -90,7 +93,13 @@ def test_modefilter(mode, expected) -> None:
         ("F", (0.0, 4.0, 8.0)),
     ),
 )
-def test_rankfilter(mode, expected) -> None:
+def test_rankfilter(
+    mode: str,
+    expected: (
+        tuple[float, float, float]
+        | tuple[tuple[int, int, int], tuple[int, int, int], tuple[int, int, int]]
+    ),
+) -> None:
     im = Image.new(mode, (3, 3), None)
     im.putdata(list(range(9)))
     # image is:
@@ -106,7 +115,7 @@ def test_rankfilter(mode, expected) -> None:
 @pytest.mark.parametrize(
     "filter", (ImageFilter.MinFilter, ImageFilter.MedianFilter, ImageFilter.MaxFilter)
 )
-def test_rankfilter_error(filter) -> None:
+def test_rankfilter_error(filter: ImageFilter.RankFilter) -> None:
     with pytest.raises(ValueError):
         im = Image.new("P", (3, 3), None)
         im.putdata(list(range(9)))
@@ -137,7 +146,7 @@ def test_kernel_not_enough_coefficients() -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
-def test_consistency_3x3(mode) -> None:
+def test_consistency_3x3(mode: str) -> None:
     with Image.open("Tests/images/hopper.bmp") as source:
         reference_name = "hopper_emboss"
         reference_name += "_I.png" if mode == "I" else ".bmp"
@@ -163,7 +172,7 @@ def test_consistency_3x3(mode) -> None:
 
 
 @pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
-def test_consistency_5x5(mode) -> None:
+def test_consistency_5x5(mode: str) -> None:
     with Image.open("Tests/images/hopper.bmp") as source:
         reference_name = "hopper_emboss_more"
         reference_name += "_I.png" if mode == "I" else ".bmp"
@@ -199,7 +208,7 @@ def test_consistency_5x5(mode) -> None:
         (2, -2),
     ),
 )
-def test_invalid_box_blur_filter(radius) -> None:
+def test_invalid_box_blur_filter(radius: int | tuple[int, int]) -> None:
     with pytest.raises(ValueError):
         ImageFilter.BoxBlur(radius)
 

Tests/test_image_getextrema.py

@@ -6,7 +6,7 @@ from .helper import hopper
 
 
 def test_extrema() -> None:
-    def extrema(mode):
+    def extrema(mode: str) -> tuple[int, int] | tuple[tuple[int, int], ...]:
         return hopper(mode).getextrema()
 
     assert extrema("1") == (0, 255)

Tests/test_image_getpalette.py

@@ -6,7 +6,7 @@ from .helper import hopper
 
 
 def test_palette() -> None:
-    def palette(mode):
+    def palette(mode: str) -> list[int] | None:
         p = hopper(mode).getpalette()
         if p:
             return p[:10]

Tests/test_image_paste.py

@@ -46,7 +46,7 @@ class TestImagingPaste:
         self.assert_9points_image(im, expected)
 
     @CachedProperty
-    def mask_1(self):
+    def mask_1(self) -> Image.Image:
         mask = Image.new("1", (self.size, self.size))
         px = mask.load()
         for y in range(mask.height):
@@ -55,11 +55,11 @@ class TestImagingPaste:
         return mask
 
     @CachedProperty
-    def mask_L(self):
+    def mask_L(self) -> Image.Image:
         return self.gradient_L.transpose(Image.Transpose.ROTATE_270)
 
     @CachedProperty
-    def gradient_L(self):
+    def gradient_L(self) -> Image.Image:
         gradient = Image.new("L", (self.size, self.size))
         px = gradient.load()
         for y in range(gradient.height):
@@ -68,7 +68,7 @@ class TestImagingPaste:
         return gradient
 
     @CachedProperty
-    def gradient_RGB(self):
+    def gradient_RGB(self) -> Image.Image:
         return Image.merge(
             "RGB",
             [
@@ -79,7 +79,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_LA(self):
+    def gradient_LA(self) -> Image.Image:
         return Image.merge(
             "LA",
             [
@@ -89,7 +89,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_RGBA(self):
+    def gradient_RGBA(self) -> Image.Image:
         return Image.merge(
             "RGBA",
             [
@@ -101,7 +101,7 @@ class TestImagingPaste:
         )
 
     @CachedProperty
-    def gradient_RGBa(self):
+    def gradient_RGBa(self) -> Image.Image:
         return Image.merge(
             "RGBa",
             [

Tests/test_image_putdata.py

@@ -31,7 +31,7 @@ def test_sanity() -> None:
 
 def test_long_integers() -> None:
     # see bug-200802-systemerror
-    def put(value):
+    def put(value: int) -> tuple[int, int, int, int]:
         im = Image.new("RGBA", (1, 1))
         im.putdata([value])
         return im.getpixel((0, 0))
@@ -58,7 +58,7 @@ def test_mode_with_L_with_float() -> None:
 
 
 @pytest.mark.parametrize("mode", ("I", "I;16", "I;16L", "I;16B"))
-def test_mode_i(mode) -> None:
+def test_mode_i(mode: str) -> None:
     src = hopper("L")
     data = list(src.getdata())
     im = Image.new(mode, src.size, 0)
@@ -79,7 +79,7 @@ def test_mode_F() -> None:
 
 
 @pytest.mark.parametrize("mode", ("BGR;15", "BGR;16", "BGR;24"))
-def test_mode_BGR(mode) -> None:
+def test_mode_BGR(mode: str) -> None:
     data = [(16, 32, 49), (32, 32, 98)]
     im = Image.new(mode, (1, 2))
     im.putdata(data)

Tests/test_image_putpalette.py

@@ -8,7 +8,7 @@ from .helper import assert_image_equal, assert_image_equal_tofile, hopper
 
 
 def test_putpalette() -> None:
-    def palette(mode):
+    def palette(mode: str) -> str | tuple[str, list[int]]:
         im = hopper(mode).copy()
         im.putpalette(list(range(256)) * 3)
         p = im.getpalette()
@@ -81,7 +81,7 @@ def test_putpalette_with_alpha_values() -> None:
         ("RGBAX", (1, 2, 3, 4, 0)),
     ),
 )
-def test_rgba_palette(mode, palette) -> None:
+def test_rgba_palette(mode: str, palette: tuple[int, ...]) -> None:
     im = Image.new("P", (1, 1))
     im.putpalette(palette, mode)
     assert im.getpalette() == [1, 2, 3]

Tests/test_image_resample.py

@@ -231,11 +231,13 @@ class TestImagingCoreResampleAccuracy:
 
 
 class TestCoreResampleConsistency:
-    def make_case(self, mode: str, fill: tuple[int, int, int] | float):
+    def make_case(
+        self, mode: str, fill: tuple[int, int, int] | float
+    ) -> tuple[Image.Image, tuple[int, ...]]:
         im = Image.new(mode, (512, 9), fill)
         return im.resize((9, 512), Image.Resampling.LANCZOS), im.load()[0, 0]
 
-    def run_case(self, case) -> None:
+    def run_case(self, case: tuple[Image.Image, Image.Image]) -> None:
         channel, color = case
         px = channel.load()
         for x in range(channel.size[0]):
@@ -353,7 +355,7 @@ class TestCoreResampleAlphaCorrect:
 
 class TestCoreResamplePasses:
     @contextmanager
-    def count(self, diff):
+    def count(self, diff: int) -> Generator[None, None, None]:
         count = Image.core.get_stats()["new_count"]
         yield
         assert Image.core.get_stats()["new_count"] - count == diff

Tests/test_image_rotate.py

@@ -12,7 +12,13 @@ from .helper import (
 )
 
 
-def rotate(im, mode, angle, center=None, translate=None) -> None:
+def rotate(
+    im: Image.Image,
+    mode: str,
+    angle: int,
+    center: tuple[int, int] | None = None,
+    translate: tuple[int, int] | None = None,
+) -> None:
     out = im.rotate(angle, center=center, translate=translate)
     assert out.mode == mode
     assert out.size == im.size  # default rotate clips output
@@ -27,13 +33,13 @@ def rotate(im, mode, angle, center=None, translate=None) -> None:
 
 
 @pytest.mark.parametrize("mode", ("1", "P", "L", "RGB", "I", "F"))
-def test_mode(mode) -> None:
+def test_mode(mode: str) -> None:
     im = hopper(mode)
     rotate(im, mode, 45)
 
 
 @pytest.mark.parametrize("angle", (0, 90, 180, 270))
-def test_angle(angle) -> None:
+def test_angle(angle: int) -> None:
     with Image.open("Tests/images/test-card.png") as im:
         rotate(im, im.mode, angle)
 
@@ -42,7 +48,7 @@ def test_angle(angle) -> None:
 
 
 @pytest.mark.parametrize("angle", (0, 45, 90, 180, 270))
-def test_zero(angle) -> None:
+def test_zero(angle: int) -> None:
     im = Image.new("RGB", (0, 0))
     rotate(im, im.mode, angle)
 

Tests/test_image_thumbnail.py

@@ -111,7 +111,7 @@ def test_load_first_unless_jpeg() -> None:
     with Image.open("Tests/images/hopper.jpg") as im:
         draft = im.draft
 
-        def im_draft(mode, size):
+        def im_draft(mode: str, size: tuple[int, int]):
             result = draft(mode, size)
             assert result is not None
 

Tests/test_image_transform.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import math
+from typing import Callable
 
 import pytest
 
@@ -91,7 +92,7 @@ class TestImageTransform:
             ("LA", (76, 0)),
         ),
     )
-    def test_fill(self, mode, expected_pixel) -> None:
+    def test_fill(self, mode: str, expected_pixel: tuple[int, ...]) -> None:
         im = hopper(mode)
         (w, h) = im.size
         transformed = im.transform(
@@ -142,7 +143,9 @@ class TestImageTransform:
         assert_image_equal(blank, transformed.crop((w // 2, 0, w, h // 2)))
         assert_image_equal(blank, transformed.crop((0, h // 2, w // 2, h)))
 
-    def _test_alpha_premult(self, op) -> None:
+    def _test_alpha_premult(
+        self, op: Callable[[Image.Image, tuple[int, int]], Image.Image]
+    ) -> None:
         # create image with half white, half black,
         # with the black half transparent.
         # do op,
@@ -159,13 +162,13 @@ class TestImageTransform:
         assert 40 * 10 == hist[-1]
 
     def test_alpha_premult_resize(self) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             return im.resize(sz, Image.Resampling.BILINEAR)
 
         self._test_alpha_premult(op)
 
     def test_alpha_premult_transform(self) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             (w, h) = im.size
             return im.transform(
                 sz, Image.Transform.EXTENT, (0, 0, w, h), Image.Resampling.BILINEAR
@@ -173,7 +176,9 @@ class TestImageTransform:
 
         self._test_alpha_premult(op)
 
-    def _test_nearest(self, op, mode) -> None:
+    def _test_nearest(
+        self, op: Callable[[Image.Image, tuple[int, int]], Image.Image], mode: str
+    ) -> None:
         # create white image with half transparent,
         # do op,
         # the image should remain white with half transparent
@@ -196,15 +201,15 @@ class TestImageTransform:
         )
 
     @pytest.mark.parametrize("mode", ("RGBA", "LA"))
-    def test_nearest_resize(self, mode) -> None:
+    def test_nearest_resize(self, mode: str) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             return im.resize(sz, Image.Resampling.NEAREST)
 
         self._test_nearest(op, mode)
 
     @pytest.mark.parametrize("mode", ("RGBA", "LA"))
-    def test_nearest_transform(self, mode) -> None:
+    def test_nearest_transform(self, mode: str) -> None:
-        def op(im, sz):
+        def op(im: Image.Image, sz: tuple[int, int]) -> Image.Image:
             (w, h) = im.size
             return im.transform(
                 sz, Image.Transform.EXTENT, (0, 0, w, h), Image.Resampling.NEAREST
@@ -227,7 +232,9 @@ class TestImageTransform:
         # Running by default, but I'd totally understand not doing it in
         # the future
 
-        pattern = [Image.new("RGBA", (1024, 1024), (a, a, a, a)) for a in range(1, 65)]
+        pattern: list[Image.Image] | None = [
+            Image.new("RGBA", (1024, 1024), (a, a, a, a)) for a in range(1, 65)
+        ]
 
         # Yeah. Watch some JIT optimize this out.
         pattern = None  # noqa: F841
@@ -240,7 +247,7 @@ class TestImageTransform:
                 im.transform((100, 100), None)
 
     @pytest.mark.parametrize("resample", (Image.Resampling.BOX, "unknown"))
-    def test_unknown_resampling_filter(self, resample) -> None:
+    def test_unknown_resampling_filter(self, resample: Image.Resampling | str) -> None:
         with hopper() as im:
             (w, h) = im.size
             with pytest.raises(ValueError):
@@ -250,7 +257,7 @@ class TestImageTransform:
 class TestImageTransformAffine:
     transform = Image.Transform.AFFINE
 
-    def _test_image(self):
+    def _test_image(self) -> Image.Image:
         im = hopper("RGB")
         return im.crop((10, 20, im.width - 10, im.height - 20))
 
@@ -263,7 +270,7 @@ class TestImageTransformAffine:
             (270, Image.Transpose.ROTATE_270),
         ),
     )
-    def test_rotate(self, deg, transpose) -> None:
+    def test_rotate(self, deg: int, transpose: Image.Transpose | None) -> None:
         im = self._test_image()
 
         angle = -math.radians(deg)
@@ -313,7 +320,13 @@ class TestImageTransformAffine:
             (Image.Resampling.BICUBIC, 1),
         ),
     )
-    def test_resize(self, scale, epsilon_scale, resample, epsilon) -> None:
+    def test_resize(
+        self,
+        scale: float,
+        epsilon_scale: float,
+        resample: Image.Resampling,
+        epsilon: int,
+    ) -> None:
         im = self._test_image()
 
         size_up = int(round(im.width * scale)), int(round(im.height * scale))
@@ -342,7 +355,14 @@ class TestImageTransformAffine:
             (Image.Resampling.BICUBIC, 1),
         ),
     )
-    def test_translate(self, x, y, epsilon_scale, resample, epsilon) -> None:
+    def test_translate(
+        self,
+        x: float,
+        y: float,
+        epsilon_scale: float,
+        resample: Image.Resampling,
+        epsilon: float,
+    ) -> None:
         im = self._test_image()
 
         size_up = int(round(im.width + x)), int(round(im.height + y))

Tests/test_imagefontctl.py

@@ -208,7 +208,9 @@ def test_language() -> None:
     ),
     ids=("None", "ltr", "rtl2", "rtl", "ttb"),
 )
-def test_getlength(mode, text, direction, expected) -> None:
+def test_getlength(
+    mode: str, text: str, direction: str | None, expected: float
+) -> None:
     ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE)
     im = Image.new(mode, (1, 1), 0)
     d = ImageDraw.Draw(im)
@@ -230,7 +232,7 @@ def test_getlength(mode, text, direction, expected) -> None:
     ("i" + ("\u030C" * 15) + "i", "i" + "\u032C" * 15 + "i", "\u035Cii", "i\u0305i"),
     ids=("caron-above", "caron-below", "double-breve", "overline"),
 )
-def test_getlength_combine(mode, direction, text) -> None:
+def test_getlength_combine(mode: str, direction: str, text: str) -> None:
     if text == "i\u0305i" and direction == "ttb":
         pytest.skip("fails with this font")
 
@@ -250,7 +252,7 @@ def test_getlength_combine(mode, direction, text) -> None:
 
 
 @pytest.mark.parametrize("anchor", ("lt", "mm", "rb", "sm"))
-def test_anchor_ttb(anchor) -> None:
+def test_anchor_ttb(anchor: str) -> None:
     text = "f"
     path = f"Tests/images/test_anchor_ttb_{text}_{anchor}.png"
     f = ImageFont.truetype("Tests/fonts/NotoSans-Regular.ttf", 120)
@@ -306,7 +308,9 @@ combine_tests = (
 @pytest.mark.parametrize(
     "name, text, anchor, dir, epsilon", combine_tests, ids=[r[0] for r in combine_tests]
 )
-def test_combine(name, text, dir, anchor, epsilon) -> None:
+def test_combine(
+    name: str, text: str, dir: str | None, anchor: str | None, epsilon: float
+) -> None:
     path = f"Tests/images/test_combine_{name}.png"
     f = ImageFont.truetype("Tests/fonts/NotoSans-Regular.ttf", 48)
 
@@ -337,7 +341,7 @@ def test_combine(name, text, dir, anchor, epsilon) -> None:
         ("rm", "right"),  # pass with getsize
     ),
 )
-def test_combine_multiline(anchor, align) -> None:
+def test_combine_multiline(anchor: str, align: str) -> None:
     # test that multiline text uses getlength, not getsize or getbbox
 
     path = f"Tests/images/test_combine_multiline_{anchor}_{align}.png"

Tests/test_imagemorph.py

@@ -10,7 +10,7 @@ from PIL import Image, ImageMorph, _imagingmorph
 from .helper import assert_image_equal_tofile, hopper
 
 
-def string_to_img(image_string):
+def string_to_img(image_string: str) -> Image.Image:
     """Turn a string image representation into a binary image"""
     rows = [s for s in image_string.replace(" ", "").split("\n") if len(s)]
     height = len(rows)
@@ -38,7 +38,7 @@ A = string_to_img(
 )
 
 
-def img_to_string(im):
+def img_to_string(im: Image.Image) -> str:
     """Turn a (small) binary image into a string representation"""
     chars = ".1"
     width, height = im.size
@@ -48,11 +48,11 @@ def img_to_string(im):
     )
 
 
-def img_string_normalize(im):
+def img_string_normalize(im: str) -> str:
     return img_to_string(string_to_img(im))
 
 
-def assert_img_equal_img_string(a, b_string) -> None:
+def assert_img_equal_img_string(a: Image.Image, b_string: str) -> None:
     assert img_to_string(a) == img_string_normalize(b_string)
 
 
@@ -63,7 +63,7 @@ def test_str_to_img() -> None:
 @pytest.mark.parametrize(
     "op", ("corner", "dilation4", "dilation8", "erosion4", "erosion8", "edge")
 )
-def test_lut(op) -> None:
+def test_lut(op: str) -> None:
     lb = ImageMorph.LutBuilder(op_name=op)
     assert lb.get_lut() is None
 

Tests/test_imagepalette.py

@@ -67,7 +67,7 @@ def test_getcolor_rgba_color_rgb_palette() -> None:
         (255, ImagePalette.ImagePalette("RGB", list(range(256)) * 3)),
     ],
 )
-def test_getcolor_not_special(index, palette) -> None:
+def test_getcolor_not_special(index: int, palette: ImagePalette.ImagePalette) -> None:
     im = Image.new("P", (1, 1))
 
     # Do not use transparency index as a new color

Tests/test_pickle.py

@@ -13,7 +13,9 @@ FONT_SIZE = 20
 FONT_PATH = "Tests/fonts/DejaVuSans/DejaVuSans.ttf"
 
 
-def helper_pickle_file(tmp_path: Path, pickle, protocol, test_file, mode) -> None:
+def helper_pickle_file(
+    tmp_path: Path, protocol: int, test_file: str, mode: str | None
+) -> None:
     # Arrange
     with Image.open(test_file) as im:
         filename = str(tmp_path / "temp.pkl")
@@ -30,7 +32,7 @@ def helper_pickle_file(tmp_path: Path, pickle, protocol, test_file, mode) -> Non
         assert im == loaded_im
 
 
-def helper_pickle_string(pickle, protocol, test_file, mode) -> None:
+def helper_pickle_string(protocol: int, test_file: str, mode: str | None) -> None:
     with Image.open(test_file) as im:
         if mode:
             im = im.convert(mode)
@@ -64,10 +66,12 @@ def helper_pickle_string(pickle, protocol, test_file, mode) -> None:
     ],
 )
 @pytest.mark.parametrize("protocol", range(0, pickle.HIGHEST_PROTOCOL + 1))
-def test_pickle_image(tmp_path: Path, test_file, test_mode, protocol) -> None:
+def test_pickle_image(
+    tmp_path: Path, test_file: str, test_mode: str | None, protocol: int
+) -> None:
     # Act / Assert
-    helper_pickle_string(pickle, protocol, test_file, test_mode)
+    helper_pickle_string(protocol, test_file, test_mode)
-    helper_pickle_file(tmp_path, pickle, protocol, test_file, test_mode)
+    helper_pickle_file(tmp_path, protocol, test_file, test_mode)
 
 
 def test_pickle_la_mode_with_palette(tmp_path: Path) -> None:
@@ -99,7 +103,9 @@ def test_pickle_tell() -> None:
     assert unpickled_image.tell() == 0
 
 
-def helper_assert_pickled_font_images(font1, font2) -> None:
+def helper_assert_pickled_font_images(
+    font1: ImageFont.FreeTypeFont, font2: ImageFont.FreeTypeFont
+) -> None:
     # Arrange
     im1 = Image.new(mode="RGBA", size=(300, 100))
     im2 = Image.new(mode="RGBA", size=(300, 100))
@@ -117,7 +123,7 @@ def helper_assert_pickled_font_images(font1, font2) -> None:
 
 @skip_unless_feature("freetype2")
 @pytest.mark.parametrize("protocol", list(range(0, pickle.HIGHEST_PROTOCOL + 1)))
-def test_pickle_font_string(protocol) -> None:
+def test_pickle_font_string(protocol: int) -> None:
     # Arrange
     font = ImageFont.truetype(FONT_PATH, FONT_SIZE)
 
@@ -131,7 +137,7 @@ def test_pickle_font_string(protocol) -> None:
 
 @skip_unless_feature("freetype2")
 @pytest.mark.parametrize("protocol", list(range(0, pickle.HIGHEST_PROTOCOL + 1)))
-def test_pickle_font_file(tmp_path: Path, protocol) -> None:
+def test_pickle_font_file(tmp_path: Path, protocol: int) -> None:
     # Arrange
     font = ImageFont.truetype(FONT_PATH, FONT_SIZE)
     filename = str(tmp_path / "temp.pkl")

Tests/test_psdraw.py

@@ -10,7 +10,7 @@ import pytest
 from PIL import Image, PSDraw
 
 
-def _create_document(ps) -> None:
+def _create_document(ps: PSDraw.PSDraw) -> None:
     title = "hopper"
     box = (1 * 72, 2 * 72, 7 * 72, 10 * 72)  # in points
 
@@ -50,7 +50,7 @@ def test_draw_postscript(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("buffer", (True, False))
-def test_stdout(buffer) -> None:
+def test_stdout(buffer: bool) -> None:
     # Temporarily redirect stdout
     old_stdout = sys.stdout
 

Tests/test_sgi_crash.py

@@ -21,7 +21,7 @@ from PIL import Image
         "Tests/images/crash-db8bfa78b19721225425530c5946217720d7df4e.sgi",
     ],
 )
-def test_crashes(test_file) -> None:
+def test_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):

Tests/test_shell_injection.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import shutil
 from pathlib import Path
+from typing import Callable
 
 import pytest
 
@@ -17,7 +18,12 @@ test_filenames = ("temp_';", 'temp_";', "temp_'\"|", "temp_'\"||", "temp_'\"&&")
 
 @pytest.mark.skipif(is_win32(), reason="Requires Unix or macOS")
 class TestShellInjection:
-    def assert_save_filename_check(self, tmp_path: Path, src_img, save_func) -> None:
+    def assert_save_filename_check(
+        self,
+        tmp_path: Path,
+        src_img: Image.Image,
+        save_func: Callable[[Image.Image, int, str], None],
+    ) -> None:
         for filename in test_filenames:
             dest_file = str(tmp_path / filename)
             save_func(src_img, 0, dest_file)

Tests/test_tiff_crashes.py

@@ -42,7 +42,7 @@ from .helper import on_ci
 @pytest.mark.filterwarnings("ignore:Possibly corrupt EXIF data")
 @pytest.mark.filterwarnings("ignore:Metadata warning")
 @pytest.mark.filterwarnings("ignore:Truncated File Read")
-def test_tiff_crashes(test_file):
+def test_tiff_crashes(test_file: str) -> None:
     try:
         with Image.open(test_file) as im:
             im.load()

Tests/test_tiff_ifdrational.py

@@ -53,9 +53,9 @@ def test_nonetype() -> None:
 
 
 def test_ifd_rational_save(tmp_path: Path) -> None:
-    methods = (True, False)
+    methods = [True]
-    if not features.check("libtiff"):
+    if features.check("libtiff"):
-        methods = (False,)
+        methods.append(False)
 
     for libtiff in methods:
         TiffImagePlugin.WRITE_LIBTIFF = libtiff

Tests/test_util.py

@@ -1,29 +1,16 @@
 from __future__ import annotations
 
-from pathlib import Path
+from pathlib import Path, PurePath
 
 import pytest
 
 from PIL import _util
 
 
-def test_is_path() -> None:
+@pytest.mark.parametrize(
-    # Arrange
+    "test_path", ["filename.ext", Path("filename.ext"), PurePath("filename.ext")]
-    fp = "filename.ext"
+)
-
+def test_is_path(test_path) -> None:
-    # Act
-    it_is = _util.is_path(fp)
-
-    # Assert
-    assert it_is
-
-
-def test_path_obj_is_path() -> None:
-    # Arrange
-    from pathlib import Path
-
-    test_path = Path("filename.ext")
-
     # Act
     it_is = _util.is_path(test_path)
 

docs/reference/internal_design.rst

@@ -1,5 +1,5 @@
-Internal Reference Docs
+Internal Reference
-=======================
+==================
 
 .. toctree::
   :maxdepth: 2

docs/reference/internal_modules.rst

@@ -33,6 +33,14 @@ Internal Modules
 Provides a convenient way to import type hints that are not available
 on some Python versions.
 
+.. py:class:: StrOrBytesPath
+
+    Typing alias.
+
+.. py:class:: SupportsRead
+
+    An object that supports the read method.
+
 .. py:data:: TypeGuard
     :value: typing.TypeGuard
 

docs/reference/open_files.rst

@@ -3,7 +3,7 @@
 File Handling in Pillow
 =======================
 
-When opening a file as an image, Pillow requires a filename, ``pathlib.Path``
+When opening a file as an image, Pillow requires a filename, ``os.PathLike``
 object, or a file-like object. Pillow uses the filename or ``Path`` to open a
 file, so for the rest of this article, they will all be treated as a file-like
 object.

src/PIL/GdImageFile.py

@@ -27,11 +27,12 @@
 """
 from __future__ import annotations
 
-from io import BytesIO
+from typing import IO
 
 from . import ImageFile, ImagePalette, UnidentifiedImageError
 from ._binary import i16be as i16
 from ._binary import i32be as i32
+from ._typing import StrOrBytesPath
 
 
 class GdImageFile(ImageFile.ImageFile):
@@ -80,7 +81,7 @@ class GdImageFile(ImageFile.ImageFile):
         ]
 
 
-def open(fp: BytesIO, mode: str = "r") -> GdImageFile:
+def open(fp: StrOrBytesPath | IO[bytes], mode: str = "r") -> GdImageFile:
     """
     Load texture from a GD image file.
 

src/PIL/Image.py

@@ -40,7 +40,6 @@ import tempfile
 import warnings
 from collections.abc import Callable, MutableMapping
 from enum import IntEnum
-from pathlib import Path
 from types import ModuleType
 from typing import IO, TYPE_CHECKING, Any
 
@@ -2383,7 +2382,7 @@ class Image:
         implement the ``seek``, ``tell``, and ``write``
         methods, and be opened in binary mode.
 
-        :param fp: A filename (string), pathlib.Path object or file object.
+        :param fp: A filename (string), os.PathLike object or file object.
         :param format: Optional format override.  If omitted, the
            format to use is determined from the filename extension.
            If a file object was used instead of a filename, this
@@ -2398,11 +2397,8 @@ class Image:
 
         filename: str | bytes = ""
         open_fp = False
-        if isinstance(fp, Path):
+        if is_path(fp):
-            filename = str(fp)
+            filename = os.path.realpath(os.fspath(fp))
-            open_fp = True
-        elif isinstance(fp, (str, bytes)):
-            filename = fp
             open_fp = True
         elif fp == sys.stdout:
             try:
@@ -3225,7 +3221,7 @@ def open(fp, mode="r", formats=None) -> Image:
     :py:meth:`~PIL.Image.Image.load` method).  See
     :py:func:`~PIL.Image.new`. See :ref:`file-handling`.
 
-    :param fp: A filename (string), pathlib.Path object or a file object.
+    :param fp: A filename (string), os.PathLike object or a file object.
        The file object must implement ``file.read``,
        ``file.seek``, and ``file.tell`` methods,
        and be opened in binary mode. The file object will also seek to zero

src/PIL/ImageFont.py

@@ -33,10 +33,10 @@ import sys
 import warnings
 from enum import IntEnum
 from io import BytesIO
-from pathlib import Path
 from typing import BinaryIO
 
 from . import Image
+from ._typing import StrOrBytesPath
 from ._util import is_directory, is_path
 
 
@@ -193,7 +193,7 @@ class FreeTypeFont:
 
     def __init__(
         self,
-        font: bytes | str | Path | BinaryIO | None = None,
+        font: StrOrBytesPath | BinaryIO | None = None,
         size: float = 10,
         index: int = 0,
         encoding: str = "",
@@ -230,8 +230,7 @@ class FreeTypeFont:
             )
 
         if is_path(font):
-            if isinstance(font, Path):
+            font = os.path.realpath(os.fspath(font))
-                font = str(font)
             if sys.platform == "win32":
                 font_bytes_path = font if isinstance(font, bytes) else font.encode()
                 try:

src/PIL/MpegImagePlugin.py

@@ -14,17 +14,16 @@
 #
 from __future__ import annotations
 
-from io import BytesIO
-
 from . import Image, ImageFile
 from ._binary import i8
+from ._typing import SupportsRead
 
 #
 # Bitstream parser
 
 
 class BitStream:
-    def __init__(self, fp: BytesIO) -> None:
+    def __init__(self, fp: SupportsRead[bytes]) -> None:
         self.fp = fp
         self.bits = 0
         self.bitbuffer = 0

src/PIL/_typing.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+import os
 import sys
-from typing import Sequence, Union
+from typing import Protocol, Sequence, TypeVar, Union
 
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
@@ -19,4 +20,14 @@ else:
 Coords = Union[Sequence[float], Sequence[Sequence[float]]]
 
 
-__all__ = ["TypeGuard"]
+_T_co = TypeVar("_T_co", covariant=True)
+
+
+class SupportsRead(Protocol[_T_co]):
+    def read(self, __length: int = ...) -> _T_co: ...
+
+
+StrOrBytesPath = Union[str, bytes, "os.PathLike[str]", "os.PathLike[bytes]"]
+
+
+__all__ = ["TypeGuard", "StrOrBytesPath", "SupportsRead"]

src/PIL/_util.py

@@ -1,17 +1,16 @@
 from __future__ import annotations
 
 import os
-from pathlib import Path
 from typing import Any, NoReturn
 
-from ._typing import TypeGuard
+from ._typing import StrOrBytesPath, TypeGuard
 
 
-def is_path(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
-    return isinstance(f, (bytes, str, Path))
+    return isinstance(f, (bytes, str, os.PathLike))
 
 
-def is_directory(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_directory(f: Any) -> TypeGuard[StrOrBytesPath]:
     """Checks if an object is a string, and that it points to a directory."""
     return is_path(f) and os.path.isdir(f)