[Python] TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

有時候安裝一個簡單的 Python 套件也會出現這樣的錯誤訊息

TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

先更新 pip 試試看吧

sudo apt-get remove python-pip python3-pip
sudo wget https://bootstrap.pypa.io/get-pip.py
sudo python get-pip.py
sudo python3 get-pip.py

如果更新以後出了問題，例如

Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in 
    from pip import main
ImportError: cannot import name main

那就修改 /usr/bin/pip
從

from pip import main
if __name__ == '__main__':
    sys.exit(main())

改為

from pip import __main__
if __name__ == '__main__':
    sys.exit(__main__._main())

 https://stackoverflow.com/questions/37495375