Command-line interfaces don't handle keywords

[arogozhnikov]

Contents for testhug.py

import hug

def hello_world(name1: str, name2: str):
    return f"Hello {name1} and {name2}"

if __name__ == '__main__':
    api = hug.API(__name__)
    hug.cli('hello_world', api=api)(hello_world)
    api.cli()

> python testhug.py hello_world --name1 1 --name2 2
Hello 1 and 2
> python testhug.py hello_world --name2 1 --name1 2
Hello 1 and 2
> python testhug.py hello_world --name2 1 --name1123 2
Hello 1 and 2

Keywords are ignored. I see CLI is not in priority, but if that's expected behavior, this should be documented well (one wouldn't expect CLI to behave like this).

Liked concept a lot though.

[Peter200lx]

Currently you have no default values for the parameters, making them positional instead of keyword arguments:

$ python testhug.py hello_world --help
usage: testhug.py [-h] name1 name2

positional arguments:
  name1       String
  name2       String

optional arguments:
  -h, --help  show this help message and exit

If you modify the code to have default values then you can address them by keywords:

import hug

def hello_world(name1: str = "First", name2: str = "Second"):
    return f"Hello {name1} and {name2}"

if __name__ == '__main__':
    api = hug.API(__name__)
    hello_world = hug.cli('hello_world', api=api)(hello_world)
    api.cli()

$ python testhug.py hello_world --help
usage: testhug.py [-h] [-n NAME1] [-na NAME2]

optional arguments:
  -h, --help            show this help message and exit
  -n NAME1, --name1 NAME1
                        String
  -na NAME2, --name2 NAME2
                        String
$ python testhug.py hello_world --name1 2 --name2 1
Hello 2 and 1
$ python testhug.py hello_world --name1 2
Hello 2 and Second

In this case I think the primary confusion for this issue is that hug is ignoring keywords it does not recognize instead of warning the user about unexpected arguments.

[arogozhnikov]

@Peter200lx sure, I've noticed that.

However that's not expected behavior. Possible options are

• allow passing positional arguments by name (just as in python). Python has / to mark arguments that should not be called by name
• raise an error and inform that --name1 and --name2 are not among allowed keywords

[Peter200lx]

General CLI patterns doesn't really agree with the first option, positional arguments and keyword arguments are two very different things. In the last line of my previous comment I agree that it is bad behavior that HUG ignores keyword arguments that it doesn't recognize. You can see this as you can pass any keyword argument:

$ python testhug.py hello_world --asdf --doesnt-exist
Hello First and Second

I believe the bug here is that hug is ignoring CLI options it doesn't specifically recognize.