设置Python pypi镜像源

清华：

python -m pip install --upgrade pip
pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple

中科大：

python -m pip install -i https://mirrors.ustc.edu.cn/pypi/simple pip -U
pip config set global.index-url https://mirrors.ustc.edu.cn/pypi/simple

阿里：

python -m pip install --upgrade pip
pip config set global.index-url https://mirrors.aliyun.com/pypi/simple