Matplotlib AttributeError: module 'matplotlib.cbook' has no attribute '_define_aliases'

I had this exact error .The problem was that 2 packages of matplotlib was installed one by conda and one by pip

To test for this:

$ conda list matplotlib

matplotlib 2.0.2 np113py35_0 matplotlib 2.1.1

Problem! Fix:

$ pip uninstall matplotlib

Probably a good idea to force matplotlib upgrade to the version pip wanted:

$ conda install matplotlib=2.1.1