如何在代理后面使用pip

$ sudo pip3 install numpy --proxy http://:

例如：

$ pip3 install --upgrade pip --proxy http://10.144.1.10:8080
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: pip in ./.local/lib/python3.8/site-packages (21.1.1)
Collecting pip
  Downloading pip-21.2.4-py3-none-any.whl (1.6 MB)
     |████████████████████████████████| 1.6 MB 768 kB/s 
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.1.1
    Uninstalling pip-21.1.1:
      Successfully uninstalled pip-21.1.1
Successfully installed pip-21.2.4