2.2 最快查看包搜索路径的方式

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当你使用 import 导入一个包或模块时，Python 会去一些目录下查找，而这些目录是有优先级顺序的，正常人会使用 sys.path 查看。

>>> import sys
>>> from pprint import pprint
>>> pprint(sys.path)
['',
 '/usr/local/Python3.7/lib/python37.zip',
 '/usr/local/Python3.7/lib/python3.7',
 '/usr/local/Python3.7/lib/python3.7/lib-dynload',
 '/home/wangbm/.local/lib/python3.7/site-packages',
 '/usr/local/Python3.7/lib/python3.7/site-packages']
>>>

那有没有更快的方式呢？

我这有一种连 console 模式都不用进入的方法呢？

你可能会想到这种，但这本质上与上面并无区别

[wangbm@localhost ~]$ python -c "print('\n'.join(__import__('sys').path))"

/usr/lib/python2.7/site-packages/pip-18.1-py2.7.egg
/usr/lib/python2.7/site-packages/redis-3.0.1-py2.7.egg
/usr/lib64/python27.zip
/usr/lib64/python2.7
/usr/lib64/python2.7/plat-linux2
/usr/lib64/python2.7/lib-tk
/usr/lib64/python2.7/lib-old
/usr/lib64/python2.7/lib-dynload
/home/wangbm/.local/lib/python2.7/site-packages
/usr/lib64/python2.7/site-packages
/usr/lib64/python2.7/site-packages/gtk-2.0
/usr/lib/python2.7/site-packages

这里我要介绍的是比上面两种都方便的多的方法，一行命令即可解决

[wangbm@localhost ~]$ python3 -m site
sys.path = [
    '/home/wangbm',
    '/usr/local/Python3.7/lib/python37.zip',
    '/usr/local/Python3.7/lib/python3.7',
    '/usr/local/Python3.7/lib/python3.7/lib-dynload',
    '/home/wangbm/.local/lib/python3.7/site-packages',
    '/usr/local/Python3.7/lib/python3.7/site-packages',
]
USER_BASE: '/home/wangbm/.local' (exists)
USER_SITE: '/home/wangbm/.local/lib/python3.7/site-packages' (exists)
ENABLE_USER_SITE: True

从输出你可以发现，这个列的路径会比 sys.path 更全，它包含了用户环境的目录。

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