What is Python's argparse module?

The argparse module parses command-line arguments for Python scripts. Create a parser: parser = argparse.ArgumentParser(description="Process files"); parser.add_argument("filename", help="Input file"); parser.add_argument("-v", "--verbose", action="store_true"); parser.add_argument("-n", "--count", type=int, default=10); args = parser.parse_args(). Access: args.filename, args.verbose, args.count. Argument types: positional (required), optional (-v/--verbose), action="store_true" (flag), choices=["json", "csv"] (restricted values), nargs="+" (one or more). Subparsers for sub-commands: parser.add_subparsers(dest="command"). Auto-generates --help. Alternatives: click (decorator-based, more ergonomic), typer (uses type hints for argument definition — modern favorite).