配置pip国内源 pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple

在windows命令行中输入：

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

即可设置pip下载源为国内源。

参考：

https://github.com/TommyZihao/zihaopython/blob/master/%E4%B8%80%E5%8A%B3%E6%B0%B8%E9%80%B8%E5%AE%89%E8%A3%85%E5%92%8C%E9%85%8D%E7%BD%AEpython3.7.2%EF%BC%88%E6%96%B0%E6%89%8B%E5%BF%85%E8%AF%BB%EF%BC%89.md