- if self._edgecolors == 'None':
+ if self._edgecolors is 'None': self._edgecolors = self._facecolors
You need to be careful when using 'is' for comparisons. This tests to
see if two objects actually share the same pointer in memory. This is
appropriate for the object None, but not the string 'None'
x = 'None'
y = x.capitalize()
x is y
matplotlib uses the string 'None' in some cases because the object
None is already used to mean "do the default thing using rc"