No module named 'pip._internal'

報錯：

Traceback (most recent call last):
File "/home/myuser/.local/bin/pip", line 7, in <module>
from pip._internal import main
ImportError: No module named 'pip._internal'

解決方法：

重新安裝pip

執行下面兩條命令：

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3.5 get-pip.py --force-reinstall