Python script: hello

hello.py

import os
import argparse
from typing import Optional

DEFAULT = os.environ.get("DEFAULT", "world")

def hello(name: Optional[str] = None):
    print(f"Hello, {name or DEFAULT}.")
    

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--name", type=str, default=DEFAULT)
    args = parser.parse_args()
    hello(name=args.name)


main()