Appease the PEP8 gods. Somewhat of a sacraficial lamb if you ask me.

cbreeden · cbreeden · commit ba0905849a8f · 2015-11-07T07:55:28.000-06:00
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -1503,6 +1503,7 @@ def thumbnail(infile, thumbfile, scale=0.1, interpolation='bilinear',
     fig.savefig(thumbfile, dpi=dpi)
     return fig
 
+
 def flatten_rgba(src, bg=None):
     """
     Flatten an RGBA image *src* with a background color *bg*.
@@ -1517,7 +1518,7 @@ def flatten_rgba(src, bg=None):
 
     bg  : Tuple(int,int,int), optional
         Background color to merge *src* with.  If no bg color is provided
-        the color from the rcParam 'savefig.facecolor' will be use.
+        the color from the rcParam 'savefig.facecolor' will be used.
 
     Returns
     -------
@@ -1529,18 +1530,18 @@ def flatten_rgba(src, bg=None):
                  rcParams.get('savefig.facecolor', 'white'))
         bg = tuple([int(x * 255.0) for x in bg])
 
-    # Numpy images have dtype=uint8 which will overflow
+    # Numpy images have dtype=uint8 which will overflow for these calculations
     src = src.astype(np.uint16)
 
-    alpha = src[:,:,3]
-    src_rgb = src[:,:,:3]
+    alpha = src[:, :, 3]
+    src_rgb = src[:, :, :3]
     w, h, _ = src.shape
 
     dest = np.empty((w, h, 4))
-    dest[:,:,0] = (255 - alpha)*bg[0] + alpha*src_rgb[:,:,0]
-    dest[:,:,1] = (255 - alpha)*bg[1] + alpha*src_rgb[:,:,1]
-    dest[:,:,2] = (255 - alpha)*bg[2] + alpha*src_rgb[:,:,2]
+    dest[:, :, 0] = (255 - alpha)*bg[0] + alpha*src_rgb[:, :, 0]
+    dest[:, :, 1] = (255 - alpha)*bg[1] + alpha*src_rgb[:, :, 1]
+    dest[:, :, 2] = (255 - alpha)*bg[2] + alpha*src_rgb[:, :, 2]
     dest = (dest/255).astype(np.uint8)
-    dest[:,:,3] = 255
+    dest[:, :, 3] = 255
 
     return dest
