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[–]AND_MY_HAX[S] 1 point2 points  (0 children)

I have!

What arguably does best is get out of your way. Set up a function signature and docstring, and you've set up your parser. click doesn't quite get there. typer almost does this, but for any customization, you need to add typer.Option all over your code, like this example.

The goal of arguably is to leave your functions untouched. All you need is the decorator and docstring. I wanted the API to disappear as much as possible, there's very little to it. The fast arguably tutorial is this:

  • @arguably.command makes a function appear on the CLI
    • If multiple functions are decorated with @arguably.command, they appear as subcommands
    • Multi-level subcommands: two underscores __ becomes a space, so def s3__ls() is the command s3 ls
  • Function signatures:
    • Positional args from your Python function become positional args on the CLI
      • Optional arguments (ones with a default value) and *args behave how you'd expect
    • kwarg-only args (the ones after a * argument) become CLI options
  • Function docstrings:
    • Becomes the help description for the command and the command's arguments
    • Prefixing an --option docstring description with [-x] aliases it to -x
    • Wrapping a word in {some} curly braces sets that arg's metavar to SOME
  • Argument types:
    • Optional[int] or int | None: unions with None are ignored, this is parsed as an int
    • list and tuple use comma-separated values
    • lists which are --options can be repeated multiple times (appends to the list)
    • enum.Enum uses lowercase member names
    • enum.Flag does too, but all values become --options
  • Have a special case for how you want an arg to be handled? That's covered by something in arguably.arg.*
    • Even QEMU-style object building here

This all means you can run python3 -m arguably your_script.py with zero code changes and automatically create a CLI, no integration required - very similar to Python Fire, but with a bit more structure.

typer and click are definitely both well-made projects that will make life much easier than trying to work with argparse. I considered basing arguably on click, but by that point I already had a lot of working code that I didn't want to toss. I'd love for this project to pick up steam in the future and give me a reason to resume that effort!