CLI Command Parser

CLI Command Parser is a class-based CLI argument parser that defines parameters with descriptors. It provides the tools to quickly and easily get started with basic CLIs, and it scales well to support even very large and complex CLIs while remaining readable and easy to maintain.

The primary goals of this project:

Make it easy to define subcommands and actions in an clean and organized manner
Allow for inheritance so that common parameters don’t need to be repeated
Make it easy to handle common initialization tasks for all actions / subcommands once
Reduce the amount of boilerplate code that is necessary for setting up parsing and handling argument values

Example Program

from cli_command_parser import Command, Option, main

class Hello(Command, description='Simple greeting example'):
    name = Option('-n', default='World', help='The person to say hello to')
    count: int = Option('-c', default=1, help='Number of times to repeat the message')

    def main(self):
        for _ in range(self.count):
            print(f'Hello {self.name}!')

if __name__ == '__main__':
    main()

$ hello_world.py --name Bob -c 3
Hello Bob!
Hello Bob!
Hello Bob!

$ hello_world.py -h
usage: hello_world.py [--name NAME] [--count COUNT] [--help]

Simple greeting example

Optional arguments:
  --name NAME, -n NAME        The person to say hello to (default: 'World')
  --count COUNT, -c COUNT     Number of times to repeat the message (default: 1)
  --help, -h                  Show this help message and exit

Installing CLI Command Parser

CLI Command Parser can be installed and updated via pip:

$ pip install -U cli-command-parser

There are no required dependencies. Support for formatting wide characters correctly in help text descriptions can be included by adding wcwidth to your project’s requirements, and/or by installing with optional dependencies:

$ pip install -U cli-command-parser[wcwidth]

Python Version Compatibility

Python versions 3.9 and above are currently supported. The last release of CLI Command Parser that supported 3.8 was 2024-09-07. Support for Python 3.8 officially ended on 2024-10-07.

User Guide

Building Commands

Getting Started: Introduction to Commands, Parameters, and main functions.
Commands: Explanation of special Command methods and Command inheritance.
Parameters: Introduces each Parameter type and their supported options.
Parameter Groups: How to group Parameters for help text organization or to enforce or prevent Parameter combinations.
Subcommands: How to define, use, and customize subcommands.
Input Types: Custom input types.

Configuring & Documenting Commands

Configuration: Configuration options for parsing, help text formatting, and more.
Documentation: How to generate and customize documentation and help text.
Example Scripts: Automatically generated documentation for the example scripts in this project.
Error Handling: How to define custom error handlers for exceptions that were not caught inside Commands.

Advanced

Advanced Usage: Advanced usage patterns.
Testing Commands: How to unit test Commands.
API Documentation: Lower level API documentation.

Links

Documentation: https://dskrypa.github.io/cli_command_parser/
Example Scripts: https://github.com/dskrypa/cli_command_parser/tree/main/examples
PyPI Releases: https://pypi.org/project/cli-command-parser/
Source Code: https://github.com/dskrypa/cli_command_parser
Issue Tracker: https://github.com/dskrypa/cli_command_parser/issues