python中如何安装包

使用pip安装numpy包时遇到问题

今天在给安装python中的numpy包时遇到了一下问题：
在cmd中输入pip install numpy语句后，出现：
Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: ‘c:\program files\python37\Lib\site-packages\numpy’
Consider using the --user option or check the permissions.

You are using pip version 19.0.3, however version 19.1 is available.
You should consider upgrading via the ‘python -m pip install --upgrade pip’ command.
如图：

解决办法

直接将pip install numpy
换成pip install --user numpy就可以了

如何在cmd中查看python安装了哪些包？

直接在cmd中输入pip list就行啦~