Force no options, for a required argument that can begin with dash?

[ccazabon]

Hi, all. I've used click for a fair number of scripts, but have run into an interface requirement that I can't seem to figure out how to accomplish with click's API.

Specifically, I've got a one-function script which will take no options [1], only required and optional arguments. The first argument is a floating point number, which can be positive or negative. You can see where this is going; click treats the leading dash on a negative number as introducing an option, which then raises a "no such option" error.

I can forcibly end parsing of options by invoking it as script -- -13.87 arg2 arg3..., but it's kind of ugly, considering there are no options to parse, and involves remembering to do it on every invocation.

I've tried various things without success. I'm using a single @click.command(...)-decorated function in the script, and have tried explicitly passing params= containing only Argument objects, with and without is_eager being True - I'd hoped that making Argument processing eager would consume the values before it got to option processing, but no luck.

Approaches I've looked for, but may have missed:

1. A context or command parameter to tell click "don't process options".
2. A context or global parameter/setting to tell click dash isn't an option-prefix character, i.e. set the default recognized prefix to something other than dash. This would be a hack, but would work.

Simplest version of the script:

# shift.py
import click

@click.command
@click.argument("shift", type=float, required=True)
def main(shift: float):
    print(f"Shifting by {shift}")


if __name__ == "__main__":
    main()

Running it with a positive value is fine, but a negative one fails:

$ shift.py 3.831
Shifting by 3.831

$ shift.py -3.831
Usage: shift.py [OPTIONS] SHIFT
Try 'shift.py --help' for help.

Error: No such option: -3

I would appreciate any info/suggestions on how this can be accomplished with click's existing API.

Thanks,

Charles

[1] I'd be happy if the automatic --help option could be supported, but losing it is fine if it makes the above work.

[ccazabon]

Actually, I just thought of a hack solution not using click's API:

if __name__ == "__main__":
    sys.argv = [sys.argv[0]] + ["--"] + sys.argv[1:]
    main()

It's ugly, but it works. Still might be nice to have a way to do it within click.