🌊seali

A does-one-thing-well library for building CLIs.
Designed to be trivially easy to use.

• Zero dependencies;
• Subcommands;
• Fish completions;
• Elegant --help messages (with line-breaks, tab-stops, and ANSI escape codes);
• Tiny day-to-day API: seali.{command, group, Doc, Style}.

This exists because I wanted ✨pretty help text✨ beyond what any other CLI library supports.

Installation

pip install seali

Example

import seali

@seali.command
def my_program(pos: str, /, *, someflag: bool = False):
    ...

if __name__ == "__main__":
    my_program()

python this_file.py foobar --someflag

Documentation

Available at https://docs.kidger.site/seali.

Alternatives

• fire was the main inspiration for seali.
  I love their 'trivial to use' UX: just call the library on your function. Relative to fire, we aim to minimise their massive surface area (they also allow you to decorate classes, dictionaries, ..., have an interactive mode, a trace mode, ...), and fix some UX issues (e.g. -s short flags, help messages) for a simpler more opinionated library.

• click is the 'standard' choice for Python CLIs.
  Honourary mention to other similar libraries that live in this niche, for example typer or rich-click.
  We aim to be (a) smaller/simpler and (b) offer a few nice UX features like fully customisable help messages.

• argparse is in the Python stdlib.
  This is usually noted for being highly verbose. We aim to be much easier to use.

As a particular focus, we aim to offer best-in-class help messages, with support for reflowing, tabstops, and respecting ANSI escape codes.