Set Environment variables for ArgParse in Python

cli.py

#!/usr/bin/env python3
"""
Example CLI with using envirnment variables.
"""

# I wiill put this together as a class later.

def getenviron(prefix, **kwargs):
    '''
    Get a list of environment variables and return a list for ARG Parsing overrides



    '''
    return_list = list()
    key=""
    value=""

    # KWARGS is a translation table KEY=Envionment Variable, Value is return key
    # If set scan for this list, if not use a prefix. If prefix is set, variables are limited to the prefix
    for evar in os.environ:
        if prefix or evar in kwargs.keys():
            value = os.environ.get(evar)
            # Something we can work with
            if kwargs and not prefix:
                print('Kargs Only',evar)
                key=kwargs.get(evar,None)
                print(key,value)

            elif evar.startswith(prefix) and not kwargs:
                key="--" + evar.replace(prefix,'').replace('_','-').lower()

            elif evar.startswith(prefix) and kwargs:
                key = kwargs[evar.replace(prefix,'')]

            if key:
                return_list.append(key)
                if value != 'True' and value != 'False' and value != 'None':
                    return_list.append(value)

        else:
            # ENV var we don't need
            pass


    return return_list