https://pypi.doubanio.com/simple/
阿里云https://mirrors.aliyun.com/pypi/simple/
清华大学https://pypi.tuna.tsinghua.edu.cn/simple/
https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/
pip install pip -U pip config set global.index-url https://mirrors.aliyun.com/pypi/simple/
