Traceback (most recent call last):
File "/usr/local/bin/pip", line 5, in <module>
from pip._internal.main import main
ImportError: No module named _internal.main
执行升级
sudo python -m pip install -U pip==8.0.1ImportError: No module named _internal.main
原文：https://blog.51cto.com/laok8/2447992