错误提示：
Try to run this command from the system terminal. Make sure that you use the correct version of 'pip' installed for your Python interpreter located at 'D:\Python\Python36\python.exe'.
解决办法：
换清华的仓库 ：https://pypi.tuna.tsinghua.edu.cn/simple
点击最下面的 Manage Reposioties 按钮，将原本的仓库源改成清华的仓库源。再去安装就可以了。