'import cPickle as pickle' "already defined" error

[Daenyth]

This python code generates an error. It's a common idiom and it would be good if mypy could check for it in some way.

try:
    import cPickle as pickle
except ImportError:
    import pickle

$ mypy --py2 --silent-imports bad.py
bad.py:4: error: Name 'pickle' already defined

[gvanrossum]

Thanks -- this looks like a duplicate of #1153. Additional discussion can go there.