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

Question

How can I lookup environment variables (e.g. export HG_USER from .profile) using python code in Mac OS X?

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

You can also the helper function os.getenv(varname[, value]) which will return the value of environment variable varname, and if it not present will return value which defaults to None