Python pip The principle of installation is from Python Of Official source Download to local installation
But using official sources is slower ( Sometimes very slow …), Frequent installation timeouts lead to installation failures , Waste a lot of time . Now there are many in China xx Source , Downloading from them is very fast , I personally recommend Douban source
Douban source address
https://pypi.douban.com/simple/
Installation using watercress source ：pip install -i https://pypi.douban.com/simple/ pymysql # pymysql Replace with the package name you want to install
