5.15 让我爱不释手的用户环境
===========================

.. image:: http://image.iswbm.com/20200804124133.png

当你在机器上并没有 root 权限时，如何安装 Python 的第三方包呢？

可以使用 ``pip install --user pkg``
将你的包安装在你的用户环境中，该用户环境与全局环境并不冲突，并且多用户之间相互隔离，互不影响。

.. code:: shell

   # 在全局环境中未安装 requests
   [root@localhost ~]$ pip list | grep requests
   [root@localhost ~]$ su - wangbm

   # 由于用户环境继承自全局环境，这里也未安装
   [wangbm@localhost ~]$ pip list | grep requests
   [wangbm@localhost ~]$ pip install --user requests
   [wangbm@localhost ~]$ pip list | grep requests
   requests (2.22.0)
   [wangbm@localhost ~]$

   # 从 Location 属性可发现 requests 只安装在当前用户环境中
   [wangbm@localhost ~]$ pip show requests
   ---
   Metadata-Version: 2.1
   Name: requests
   Version: 2.22.0
   Summary: Python HTTP for Humans.
   Home-page: http://python-requests.org
   Author: Kenneth Reitz
   Author-email: me@kennethreitz.org
   Installer: pip
   License: Apache 2.0
   Location: /home/wangbm/.local/lib/python2.7/site-packages
   [wangbm@localhost ~]$ exit
   logout

   # 退出 wangbm 用户，在 root 用户环境中发现 requests 未安装
   [root@localhost ~]$ pip list | grep requests
   [root@localhost ~]$