The intermixing of macos python and brew installed python has been painful for me in the past.

Specifically, I spent hours and hours trying to fix

   import matplotlib.pyplot

producing

   ImportError: cannot import name _thread

but only in ipython, not the interpreter. (HAHAHAHA fuck you developers).

A ton of googling and swearing produced the fact that a package named six that does god knows what was being read out of

   /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/six.pyc

instead of

   /Library/Python/2.7/site-packages

rm -rf'ing the former path fixed things, but fuck only knows what else I may have broken. Just because I want to plot things from ipython.

ps -- 6 months ago the above used to work. Why did it stop? I have no bloody idea. But this consumed multiple hours of my life.