Required mutually exclusive groups don't work with boolean arguments.

[Mark Gajdosik]

I have the following management command (called test.py):

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('--value', type=str)
        group.add_argument('--flag', action='store_true')

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

Running ./manage.py test --flag or ./manage.py --value foo, the command works as expected. Using call_command to call the command from my code fails if I pass --flag, e.g.:

from django.core.management import call_command

call_command('test', flag=True)

This gets me the following traceback:

argparse.ArgumentError: argument --flag: ignored explicit argument 'True'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/home/mark/.local/share/virtualenvs/backend-KlVhwr95/lib/python3.8/site-packages/django/core/management/__init__.py", line 147, in call_command
    defaults = parser.parse_args(args=parse_args)
  File "/home/mark/.local/share/virtualenvs/backend-KlVhwr95/lib/python3.8/site-packages/django/core/management/base.py", line 57, in parse_args
    return super().parse_args(args, namespace)
  File "/usr/lib/python3.8/argparse.py", line 1780, in parse_args
    args, argv = self.parse_known_args(args, namespace)
  File "/usr/lib/python3.8/argparse.py", line 1819, in parse_known_args
    self.error(str(err))
  File "/home/mark/.local/share/virtualenvs/backend-KlVhwr95/lib/python3.8/site-packages/django/core/management/base.py", line 63, in error
    raise CommandError("Error: %s" % message)
django.core.management.base.CommandError: Error: argument --flag: ignored explicit argument 'True'

[Mark Gajdosik]

Probably stating the obvious, but I get the same error when running the command from console and passing value to the --flag explicitly, e.g. ./manage.py test --flag=True.

[Mariusz Felisiak]

Please do not use Trac as a support channel. You should pass argument without a value, e.g. call_command('test', '--flag').

[Mariusz Felisiak]

Mark's response via email:

1. I'm not using your trac as a support channel. This was the first time I used it and I doubt I'll use it again.
2. RE the actual issue: docs for call_comamnd clearly state: "command options that take no arguments are passed as keywords with True or False". This works fine, until the arg is placed inside a group. The docs don't mention this.

I understand that Django devs are busy, but at least try understanding what the ticket is saying before rushing to close it. Thank you.

Kind Regards,
Mark Gajdosik

[Mariusz Felisiak]

1. I'm not using your trac as a support channel. This was the first time I used it and I doubt I'll use it again.

I'm sorry you had a bad experience. From the ticket description I assumed that you're trying to find a way to pass a boolean argument, that's why I took it as a support question.

2. RE the actual issue: docs for call_comamnd clearly state: "command options that take no arguments are passed as keywords with True or False". This works fine, until the arg is placed inside a group. The docs don't mention this.

Good catch, I can reproduce this issue for a required mutually exclusive groups with boolean arguments. We should probably change ​preparing boolean arguments before passing them to parse_args().

[Mark Gajdosik]

I'm sorry you had a bad experience. From the ticket description I assumed that you're trying to find a way to pass a boolean argument, that's why I took it as a support question.

I'm to blame for that as I failed to describe the issue clearly. Thank you for reopening the ticket and for your initial suggestion, which helped me around the issue.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 6eb3f53b:

Fixed #32047 -- Fixed call_command() crash if a constant option from required mutually exclusive group is passed in options.

[Mariusz Felisiak <felisiak.mariusz@…>]

In efe74ff:

Refs #32047 -- Added test for using call_command() with constant required options.