Amit Yadav Amit Yadav - 4 months ago 7
Python Question

Access environment variables from Python

I set an environment variable that I want to access in my Python application. How do I get this value?

Rod Rod
Answer

Environment variables are accessed through os.environ

import os
print os.environ['HOME']

Or you can see a list of all the environment variables using:

os.environ

As sometimes you might need to see a complete list!

# using get will return `None` if a key is not present rather than raise a `KeyError`
print os.environ.get('KEY_THAT_MIGHT_EXIST')

# os.getenv is equivalent, and can also give a default value instead of `None`
print os.getenv('KEY_THAT_MIGHT_EXIST', default_value)

Python default installation on Windows is C:\Python. If you want to find out while running python you can do:

import sys
print sys.prefix