Code syntax correction.

bensullivan2 · bensullivan2 · commit d83ba6a2ffdd · 2013-12-05T09:37:52.000+01:00
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -1365,9 +1365,9 @@ def shade(self, data, cmap, vmin=None, vmax=None):
         plot the shaded image with imshow.
         """
 
-        if vmin == None:
+        if vmin is None:
             vmin = data.min()
-        if vmax == None:
+        if vmax is None:
             vmax = data.max()
 
         rgb0 = cmap((data - vmin) / (vmax - vmin))
