PIP uses image website to solve the problem of slow network speed

reason

pip The installation library will access foreign servers by default

resolvent

Use domestic mirror websites

pip3 install numpy -i https://pypi.tuna.tsinghua.edu.cn/simple

-i： Specify mirror source

Mirror source

1. University of science and technology of China : https://pypi.mirrors.ustc.edu.cn/simple

2. douban ：http://pypi.douban.com/simple/

3. Tsinghua University ：https://pypi.tuna.tsinghua.edu.cn/simple