1.下载python并安装

https://www.python.org/downloads/windows/

2安装后添加环境变量

控制面板\所有控制面板项\系统->高级系统设置->环境变量->path->新建->C:\Users\houyong\AppData\Local\Programs\Python\Python39

3.下载pip

https://pypi.org/project/pip/#files

pip-21.2.2-py3-none-any.whl (1.6 MB)

安装pip:

python pip-21.2.2-py3-none-any.whl/pip install pip-21.2.2-py3-none-any.whl

D:\test>python pip-21.2.2-py3-none-any.whl/pip install pip-21.2.2-py3-none-any.whl
Processing d:\test\pip-21.2.2-py3-none-any.whl
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.1.3
    Uninstalling pip-21.1.3:
      Successfully uninstalled pip-21.1.3
  WARNING: The scripts pip.exe, pip3.9.exe and pip3.exe are installed in 'C:\Users\houyong\AppData\Local\Programs\Python\Python39\Scripts' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed pip-21.2.2

4.pip添加环境变量

C:\Users\houyong\AppData\Local\Programs\Python\Python39\Scripts