How to fetch environment variables in Mac OS X using python?

Question

如何在Mac OS X中使用python代码查找环境变量（例如从.profile导出HG_USER）？

Answer 1

os.environ is a dictionary containing all the environment variables. You need to import os before you can use it. So, for example HG_USER would be accessed by os.environ['HG_USER'] .

Answer 2

Use the os module:

import os
os.environ

Returns a dictionary with the environment variables as keys.

Answer 3

Use os :

>>> import os
>>> print os.environ["PATH"]

Answer 4

你也可以使用辅助函数os.getenv(varname[, value])来返回环境变量varname的值，如果它不存在则返回默认值为None value