Merge pull request #2793 from radarhere/contextmanager

Added context manager support

PIL/ImageFile.py

@@ -420,6 +420,12 @@ class Parser(object):
 
                 self.image = im
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
     def close(self):
         """
         (Consumer) Close the stream.

PIL/PngImagePlugin.py

@@ -118,6 +118,12 @@ class ChunkStream(object):
 
         return cid, pos, length
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
     def close(self):
         self.queue = self.crc = self.fp = None
 

Tests/test_file_png.py

@@ -504,15 +504,15 @@ class TestFilePng(PillowTestCase):
         chunks = []
         with open(test_file, "rb") as fp:
             fp.read(8)
-            png = PngImagePlugin.PngStream(fp)
-            while True:
-                cid, pos, length = png.read()
-                chunks.append(cid)
-                try:
-                    s = png.call(cid, pos, length)
-                except EOFError:
-                    break
-                png.crc(cid, s)
+            with PngImagePlugin.PngStream(fp) as png:
+                while True:
+                    cid, pos, length = png.read()
+                    chunks.append(cid)
+                    try:
+                        s = png.call(cid, pos, length)
+                    except EOFError:
+                        break
+                    png.crc(cid, s)
 
         # https://www.w3.org/TR/PNG/#5ChunkOrdering
         # IHDR - shall be first

Tests/test_imagefile.py

@@ -74,9 +74,9 @@ class TestImageFile(PillowTestCase):
     def test_ico(self):
         with open('Tests/images/python.ico', 'rb') as f:
             data = f.read()
-        p = ImageFile.Parser()
-        p.feed(data)
-        self.assertEqual((48, 48), p.image.size)
+        with ImageFile.Parser() as p:
+            p.feed(data)
+            self.assertEqual((48, 48), p.image.size)
 
     def test_safeblock(self):
         if "zip_encoder" not in codecs: