Merge pull request #2307 from radarhere/contextmanagers

Added context managers

PIL/GifImagePlugin.py

@@ -521,22 +521,20 @@ def _save_netpbm(im, fp, filename):
     import tempfile
     file = im._dump()
 
-    if im.mode != "RGB":
-        with open(filename, 'wb') as f:
-            stderr = tempfile.TemporaryFile()
-            check_call(["ppmtogif", file], stdout=f, stderr=stderr)
-    else:
-        with open(filename, 'wb') as f:
-
+    with open(filename, 'wb') as f:
+        if im.mode != "RGB":
+            with tempfile.TemporaryFile() as stderr:
+                check_call(["ppmtogif", file], stdout=f, stderr=stderr)
+        else:
             # Pipe ppmquant output into ppmtogif
             # "ppmquant 256 %s | ppmtogif > %s" % (file, filename)
             quant_cmd = ["ppmquant", "256", file]
             togif_cmd = ["ppmtogif"]
-            stderr = tempfile.TemporaryFile()
-            quant_proc = Popen(quant_cmd, stdout=PIPE, stderr=stderr)
-            stderr = tempfile.TemporaryFile()
-            togif_proc = Popen(togif_cmd, stdin=quant_proc.stdout, stdout=f,
-                               stderr=stderr)
+            with tempfile.TemporaryFile() as stderr:
+                quant_proc = Popen(quant_cmd, stdout=PIPE, stderr=stderr)
+            with tempfile.TemporaryFile() as stderr:
+                togif_proc = Popen(togif_cmd, stdin=quant_proc.stdout,
+                                   stdout=f, stderr=stderr)
 
             # Allow ppmquant to receive SIGPIPE if ppmtogif exits
             quant_proc.stdout.close()

PIL/IcnsImagePlugin.py

@@ -330,8 +330,8 @@ def _save(im, fp, filename):
     from subprocess import Popen, PIPE, CalledProcessError
 
     convert_cmd = ["iconutil", "-c", "icns", "-o", filename, iconset]
-    stderr = tempfile.TemporaryFile()
-    convert_proc = Popen(convert_cmd, stdout=PIPE, stderr=stderr)
+    with tempfile.TemporaryFile() as stderr:
+        convert_proc = Popen(convert_cmd, stdout=PIPE, stderr=stderr)
 
     convert_proc.stdout.close()
 

PIL/SpiderImagePlugin.py

@@ -83,9 +83,8 @@ def isSpiderHeader(t):
 
 
 def isSpiderImage(filename):
-    fp = open(filename, 'rb')
-    f = fp.read(92)   # read 23 * 4 bytes
-    fp.close()
+    with open(filename, 'rb') as fp:
+        f = fp.read(92)   # read 23 * 4 bytes
     t = struct.unpack('>23f', f)  # try big-endian first
     hdrlen = isSpiderHeader(t)
     if hdrlen == 0:

Tests/helper.py

@@ -151,7 +151,7 @@ def skipKnownBadTest(self, msg=None, platform=None,
 
     def tempfile(self, template):
         assert template[:5] in ("temp.", "temp_")
-        (fd, path) = tempfile.mkstemp(template[4:], template[:4])
+        fd, path = tempfile.mkstemp(template[4:], template[:4])
         os.close(fd)
 
         self.addCleanup(self.delete_tempfile, path)

Tests/test_file_gif.py

@@ -56,7 +56,7 @@ def test_optimize_correctness(self):
         # 256 color Palette image, posterize to > 128 and < 128 levels
         # Size bigger and smaller than 512x512
         # Check the palette for number of colors allocated.
-        # Check for correctness after conversion back to RGB        
+        # Check for correctness after conversion back to RGB
         def check(colors, size, expected_palette_length):
             # make an image with empty colors in the start of the palette range
             im = Image.frombytes('P', (colors,colors),
@@ -70,7 +70,7 @@ def check(colors, size, expected_palette_length):
             # check palette length
             palette_length = max(i+1 for i,v in enumerate(reloaded.histogram()) if v)
             self.assertEqual(expected_palette_length, palette_length)
-            
+
             self.assert_image_equal(im.convert('RGB'), reloaded.convert('RGB'))
 
 
@@ -271,12 +271,11 @@ def test_duration(self):
         duration = 1000
 
         out = self.tempfile('temp.gif')
-        fp = open(out, "wb")
-        im = Image.new('L', (100, 100), '#000')
-        for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, duration=duration):
-            fp.write(s)
-        fp.write(b";")
-        fp.close()
+        with open(out, "wb") as fp:
+            im = Image.new('L', (100, 100), '#000')
+            for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, duration=duration):
+                fp.write(s)
+            fp.write(b";")
         reread = Image.open(out)
 
         self.assertEqual(reread.info['duration'], duration)
@@ -329,12 +328,11 @@ def test_number_of_loops(self):
         number_of_loops = 2
 
         out = self.tempfile('temp.gif')
-        fp = open(out, "wb")
-        im = Image.new('L', (100, 100), '#000')
-        for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, loop=number_of_loops):
-            fp.write(s)
-        fp.write(b";")
-        fp.close()
+        with open(out, "wb") as fp:
+            im = Image.new('L', (100, 100), '#000')
+            for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, loop=number_of_loops):
+                fp.write(s)
+            fp.write(b";")
         reread = Image.open(out)
 
         self.assertEqual(reread.info['loop'], number_of_loops)

Tests/test_file_ppm.py

@@ -36,9 +36,8 @@ def test_16bit_pgm_write(self):
 
     def test_truncated_file(self):
         path = self.tempfile('temp.pgm')
-        f = open(path, 'w')
-        f.write('P6')
-        f.close()
+        with open(path, 'w') as f:
+            f.write('P6')
 
         self.assertRaises(ValueError, lambda: Image.open(path))
 
@@ -47,8 +46,8 @@ def test_neg_ppm(self):
         # Storage.c accepted negative values for xsize, ysize.  the
         # internal open_ppm function didn't check for sanity but it
         # has been removed. The default opener doesn't accept negative
-        # sizes. 
-        
+        # sizes.
+
         with self.assertRaises(IOError):
             Image.open('Tests/images/negative_size.ppm')
 

Tests/test_image.py

@@ -80,11 +80,11 @@ def test_tempfile(self):
         # Will error out on save on 3.0.0
         import tempfile
         im = hopper()
-        fp = tempfile.TemporaryFile()
-        im.save(fp, 'JPEG')
-        fp.seek(0)
-        reloaded = Image.open(fp)
-        self.assert_image_similar(im, reloaded, 20)
+        with tempfile.TemporaryFile() as fp:
+            im.save(fp, 'JPEG')
+            fp.seek(0)
+            reloaded = Image.open(fp)
+            self.assert_image_similar(im, reloaded, 20)
 
     def test_internals(self):
 

Tests/test_psdraw.py

@@ -35,12 +35,10 @@ def test_draw_postscript(self):
 
         # Arrange
         tempfile = self.tempfile('temp.ps')
-        fp = open(tempfile, "wb")
-
-        # Act
-        ps = PSDraw.PSDraw(fp)
-        self._create_document(ps)
-        fp.close()
+        with open(tempfile, "wb") as fp:
+            # Act
+            ps = PSDraw.PSDraw(fp)
+            self._create_document(ps)
 
         # Assert
         # Check non-zero file was created

setup.py

@@ -728,9 +728,8 @@ def add_multiarch_paths(self):
                 return
         try:
             if ret >> 8 == 0:
-                fp = open(tmpfile, 'r')
-                multiarch_path_component = fp.readline().strip()
-                fp.close()
+                with open(tmpfile, 'r') as fp:
+                    multiarch_path_component = fp.readline().strip()
                 _add_directory(self.compiler.library_dirs,
                                '/usr/lib/' + multiarch_path_component)
                 _add_directory(self.compiler.include_dirs,