python 常用命令
pip install 包名 -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com
python -m pip install --upgrade pip
python -m pip install --upgrade pip
pip install 包名 -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com
python -m pip install --upgrade pip
python -m pip install --upgrade pip