Support for list arguments inside exclusive required groups

[Mark Gajdosik]

Are there any plans to add support for the following?

from django.core.management import BaseCommand

class Command(BaseCommand):
    def add_arguments(self, parser):
        group = parser.add_mutually_exclusive_group(required=True)
        group.add_argument('--foo', nargs='+', type=int)

    def handle(self, *args, **options):
        pass

When calling the above using call_command:

call_command('call_command_test', foo=[1, 2, 3])
# Raises: django.core.management.base.CommandError: Error: argument --foo: invalid int value: '[1, 2, 3]'

call_command('call_command_test', '--foo=1', '--foo=2', '--foo=3')
# Option 'foo' will be of value [3]

I can't think of any workarounds other than setting type=str (somehow, that works fine) and coercing manually. Thank you!

[Hasan Ramezani]

I think we need to add proper handling for required arguments with nargs as well.

[Mark Gajdosik]

Replying to Hasan Ramezani:

I think we need to add proper handling for required arguments with nargs as well.

That would always be neat. I couldn't get it to work with the current {}={} syntax and the list comprehension:

# Any required arguments which are passed in via **options must be passed
# to parse_args().
for opt in parser_actions:
    if (
            opt.dest in options and
            (opt.required or opt in mutually_exclusive_required_options)
    ):
        parse_args.append(min(opt.option_strings))
        value = arg_options[opt.dest]
        if isinstance(value, (list, tuple)):
            parse_args += map(str, value)
        else:
            parse_args.append(str(value))

[Mariusz Felisiak]

Thanks for this report. Yes we should change parse_args to the list of arguments and their values without using the = syntax, e.g. pass ['--foo', '1', '2'] instead of ['--foo=1 2']. All of these calls should be supported:

management.call_command('command', '--foo 1 2')
management.call_command('command', foo=[1, 2])
management.call_command('command', foo, [1, 2])

[Hasan Ramezani]

​PR
I think we shouldn't support management.call_command('command', '--foo 1 2').
I think python argparse also doesn't support that.
Please correct me if I get it wrong.

[Mariusz Felisiak]

After reconsideration, I agree that we shouldn't support this, it's not described in the ​Option value syntax and it can be tricky to support all options.

[Mariusz Felisiak <felisiak.mariusz@…>]

In f06beea9:

Fixed #32153 -- Fixed management commands when using required list options.

Thanks Mark Gajdosik for the report and initial patch.

[Mark Gajdosik]

Thank you both for expediting this so quickly!