Use argparse to add support for command line arguments to your program. Argparse supports adding sub commands to a primary command. It also supports making your subcommands mandatory or optional. Let me jump into example & explain.

import argparse, sys

def sub_commands(add_arg):
    # Create child commands 
    # use required option to make the option mandatory
    # Use metavar to print description for what kind of input is expected
    add_arg.add_argument("--state", help='Location to tf state file',
                       metavar='<file>', required=True)
    add_arg.add_argument("--varfile", help='Location to input variables files',
                       metavar='<file>', required=True)

    return add_arg

def parse_options(args):
    parser = argparse.ArgumentParser(description='Any description to be displayed for the program.')
    # Create a subcommand
    subparsers = parser.add_subparsers(help='Add sub commands')
    # Define a primary command apply & set child/sub commands for apply
    add_p = subparsers.add_parser('apply', help='Apply your changes to system')
    add_p = subparsers.add_parser('destroy', help='Destroy the infra from system')
    add_p = subparsers.add_parser('plan', help='Verify your changes before apply')
    args = parser.parse_args()
    return args