---
id: clize
version: "5.0.2"
license: MIT
license_treatment: permissive
maintenance: dormant
---

# clize — Turn functions into command-line interfaces

License: permissive · Maintenance: dormant · Downloads: 207.7K/mo

## What it is and what it does

Clize is an argument parser that eliminates boilerplate by deriving CLI interfaces directly from Python function definitions. Instead of writing separate argparse code, you define a function with typed parameters and a docstring, pass it to clize.run(), and get a fully functional command-line tool with automatic help text, option parsing, and subcommand support.

The package works by introspecting function signatures to infer positional arguments, optional flags, and keyword arguments, then generates help messages from docstrings. It supports decorators for composing multiple commands and extending parameter behavior. Runtime dependencies are minimal (sigtools, attrs, od, docutils), and it runs on Python 3.6+ across CPython and PyPy.

Use it for:

- Build a simple CLI tool for a utility function without writing argparse boilerplate.
- Create multi-command CLI applications using decorators to compose related functions.
- Generate self-documenting command-line tools where help text comes directly from docstrings.
- Prototype command-line interfaces quickly during development before committing to a larger framework.
- Add CLI entry points to existing Python libraries by wrapping functions with clize.run().

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Clize turns Python functions into command-line interfaces automatically, generating argument parsing and help text from function signatures and docstrings instead of requiring manual argparse configuration.

Yes, for stable CLI projects. Clize is production-ready and permissively licensed, with low install friction and no known vulnerabilities. Dormant maintenance is acceptable if you need a simple, proven argument parser and do not require active feature development. Not recommended if you need ongoing support or anticipate heavy customization beyond what decorators provide.

## Install

pip install clize
uv add clize
poetry add clize

## Installing clize

Before you install: Low install friction with four lightweight runtime dependencies. Dormant maintenance (last commit 2023-11-24, 1132 days ago) but marked Production/Stable; suitable for stable CLI use cases where active development is not expected.

License in practice: MIT license (permissive); you can use, modify, and distribute clize freely in commercial and private projects with minimal restrictions.

Quickstart:

pip install clize

from clize import run

def greet(name=None):
    """Greet someone.
    
    :param name: Person to greet
    """
    return f'Hello {name or "world"}!'

if __name__ == '__main__':
    run(greet)

Verify before relying:

- Whether dormant status (no commits since 2023-11-24) poses a risk for future Python version compatibility or security patches.
- Performance characteristics compared to argparse for large CLI applications with many subcommands.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: dormant
- Downloads: 207.7K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

python cli argument parser, function to command line interface, automatic argparse alternative, cli from function signature, python command line decorator, generate help from docstring, subcommands decorator, cli-builder, argparse-alternative, decorator-based

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