Dear all,

This is probably a feature that has been proposed before, but I could not find a discussion on it, so I proposed it on the tracker, and Tim also couldn't find a discussion.

(ticket: https://code.djangoproject.com/ticket/30118 )

I would like to propose being able to write `SomeModel.objects.exists(field=value)` over `SomeModel.objects.filter(field=value).exists()` (and similar for `.count(**kwargs)`.


As Tim rightfully commented: "There should be one-- and preferably only one --obvious way to do it.".


I'm proposing this is a case where the obvious way would eventually be more in line with my suggestion instead of what we currently use.


Consider the following code example (from https://github.com/django/django/blob/709a8b861de14204f0e13c9a0fbfd61c11b3565d/tests/auth_tests/test_management.py#L998):


            Permission.objects.filter(
                content_type__model=opts.model_name,
                content_type__app_label=opts.app_label,
                codename=codename,
            ).exists()

There is a weird (to me, your mileage might vary) ").exists()" as a final line, and I would like to write this as

            Permission.objects.exists(
                content_type__model=opts.model_name,
                content_type__app_label=opts.app_label,
                codename=codename,
            )

This pattern seems to be quite rare in the Django codebase itself, but in the codebase at work we have several cases of `queryset.filter(<lots of lines>).exists()` (and similar with count), and I am expecting this to also be prevalent in other codebases out there.


Arguing against it however are the following lines of the Zen of Python:

- "Explicit is better than implicit."

- Maybe also "Special cases aren't special enough to break the rules.", because `.filter().count()` and `.exclude().count()` are both the same pattern, but this would only create an alternative for the first.

- "There should be one-- and preferably only one --obvious way to do it."


Beyond these short quips, I was hoping there might also be an earlier discussion covering this.


Kind regards,

Sjoerd Job Postmus

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