os.environ with nonexistent keys/environment variables

Question

For a python program, I am using os.environ() to get environment variables with a certain key. However, I would like to be able do something if the key is nonexistent in the environment, instead of throwing a KeyError.

I've looked up a few solutions, but os.environ.get() and os.getenv() seem to act differently than how I expect. Is there any way to use os.environ() and still work around nonexistent environment variables?

Answer 1

os.environ.get("foo")

returns None if "foo" is not found.

You can also use

if "foo" in os.environ: