Access environment variables in Python
David Y.
The Problem
How do I access environment variables in Python?
The Solution
The Python os module contains a mapping object (similar to a dictionary) called environ that stores all environment variables and their values.
import os print(os.environ) # show all environment variables and their values.
One way to access environment variables is to use os.environ like a dictionary. For example, os.environ['SHELL'] will contain the value of the SHELL environment variable. However, if the requested environment variable does not exist, trying to access it will raise a KeyError exception. Therefore, a safer way to do this is use the os.getenv function, which allows us to specify a default fallback value.
shell_ev = os.getenv('SHELL', '/bin/bash')
This code will store the value of the SHELL environment variable in shell_ev. If this environment variable does not exist, the string /bin/bash will be stored.
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