Bug report

Bug summary

• For not-so-careful beginners, misuse of import pollute six environment

Code for reproduction

For first time use after pip install matplotlib

import matplotlib as plt

Actual outcome

Traceback (most recent call last):
  File "draw_plot.py", line 4, in <module>
    import matplotlib as plt
  File "/path/to/.alexpy3/lib/python3.6/site-packages/matplotlib/__init__.py", line 129, in <module>
    from six.moves.urllib.request import urlopen
ImportError: cannot import name 'urlopen'

after this, the same import error still stays.

python
> from six.moves.urllib.request import urlopen
ImportError: cannot import name 'urlopen'

Expected outcome

• six environment should not be polluted even for misuse of matplotlib

Matplotlib version

• Matplotlib version, 2.0.0
• Python version, 3.6.0
• Platform, OSX
• How did you install Matplotlib and Python, pip