WARNING: The repository located at mirrors.aliyun.com is not a trusted or secure host and is being

在命令行中使用pip国内镜像源安装时报错提示：
WARNING: The repository located at mirrors.aliyun.com is not a trusted or secure
host and is being ignored. If this repository is available via HTTPS we recomme
nd you use HTTPS instead, otherwise you may silence this warning and allow it an
yway with ‘–trusted-host mirrors.aliyun.com’.

解决方法：末尾再加上 --trusted-host 镜像服务器地址，例如：

pip3 install PyExecJS -i http://pypi.mirrors.ustc.edu.cn/simple/ --trusted-host pypi.mirrors.aliyun.com

pip install 包名称 -i 镜像源名称 --trusted-host 镜像服务器地址

常用的国内镜像源：

清华大学 https://pypi.tuna.tsinghua.edu.cn/simple/

阿里云 http://mirrors.aliyun.com/pypi/simple/

豆瓣 http://pypi.douban.com/simple/

中国科学技术大学 http://pypi.mirrors.ustc.edu.cn/simple/

华中科技大学 http://pypi.hustunique.com/