Click
Composable command-line toolkit from the Pallets team — builds CLIs with minimal boilerplate using decorators, used by Flask, pip, and countless tools
Visit Click →Click builds command-line interfaces with decorators — @click.command() and @click.option() handle argument parsing, help text, and validation with far less boilerplate than the standard library’s argparse. It’s what Flask and pip’s own CLIs are built on.
Typer takes a newer, type-hint-driven approach to the same problem and is built on top of Click internally — worth comparing if you want CLI arguments inferred from function signatures rather than explicit decorators.