argparse

import argparse
 
def main():
    parser = argparse.ArgumentParser(prog="invoice", description="Manage invoices")
    parser.add_argument("--format", choices=["json", "csv"], default="json")
    parser.add_argument("id", type=int, nargs="?", help="Invoice ID")
    args = parser.parse_args()
    print(args)
 
if __name__ == "__main__":
    main()

import argparse
import sys
 
def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="deploy",
        description="Deploy application to environments",
    )
    parser.add_argument("--verbose", "-v", action="count", default=0)
    sub = parser.add_subparsers(dest="env", required=True)
 
    for name in ("staging", "production"):
        p = sub.add_parser(name, help=f"Deploy to {name}")
        p.add_argument("--dry-run", action="store_true")
        p.add_argument("--tag", required=True, help="Docker image tag")
    return parser
 
def main(argv: list[str] | None = None) -> int:
    args = build_parser().parse_args(argv)
    if args.verbose:
        print(f"Deploying {args.tag} to {args.env}", file=sys.stderr)
    if args.dry_run:
        print("Dry run - no changes made")
        return 0
    # deploy logic here
    return 0
 
if __name__ == "__main__":
    raise SystemExit(main())