Simple environment variable helper

env.py

"""
All environment variable access should be performed via this module.
- allows tracing of where variables are used
- provide sensible defaults
- reduce string typos
"""
import os
import sys

SIZE = '10'
COLOR = 'red'

# Magic: Override locals with environment settings
for key in dict(locals()):
    if key in os.environ:
        setattr(sys.modules[__name__], key, os.getenv(key))