In Python, how to get the value (string) of an environment variable?
In Python, all environment variables can be accessed directly through os.environ
import os
print os.environ['HOME']
If the environment variable is not present, it will raise a KeyError
.
You can use get
to return None
if the environment variable is not present:
print os.environ.get('ENV_MIGHT_EXIST')
os.getenv()
is a handy function. It can give a default value instead or None
# return the default value if the environment variable is not present
print os.getenv('ENV_MIGHT_EXIST', 'ENV_DEFAULT_VAL')
# return `None` if the environment variable is not present
print os.getenv('ENV_MIGHT_EXIST')