Admindocs does not recognize methods containing positional-only arguments or keyword-only arguments as such

[David Sanders]

Given the model:

class Foo(Model):
    def arg_kwarg_method(self, arg, kwarg=None): ...
    def posarg_only_method(self, posarg, /): ...
    def kwarg_only_method(self, *, kwarg): ...
    def posarg_only_and_kwarg_only_method(self, posarg, /, *, kwarg): ...
    def posarg_only_and_arg_and_kwarg_only_method(self, posarg, /, arg, *, kwarg): ...

The following are documented as methods:

• arg_kwarg_method()
• posarg_only_method()
• posarg_only_and_kwarg_only_method()

The following are documented as attributes:

• kwarg_only_method()
• posarg_only_and_arg_and_kwarg_only_method()

[David Sanders]

Screenshot of admindocs treating some methods as attributes

[Natalia Bidart]

After some investigation, this definitely seems like a valid issue. I did some initial debugging, and both methods are being detected as fields because the guard (in django/contrib/admindocs/views.py:ModelDetailView):

                elif (
                    method_has_no_args(func)
                    and not func_accepts_kwargs(func)
                    and not func_accepts_var_args(func)
                ):
                    fields.append(
                        {
                            "name": func_name,
                            "data_type": get_return_data_type(func_name),
                            "verbose": verbose or "",
                        }
                    )

is being evaluated with these values:

method_has_no_args(func)=True func_accepts_kwargs(func)=False func_accepts_var_args(func)=False

The methods func_accepts_kwargs and func_accepts_var_args need to be updated to understand the * and / syntax (new since Python 3.8).
David, would you like to prepare a patch? :-)

[Salvo Polizzi]

PR: ​https://github.com/django/django/pull/17848

[David Sanders]

Hi Salvo,

Thanks for picking this up. You're in the right areaa but the patch provided appears to break the patched functions.

My advice is to start with creating a test for admindocs first then take a look at the function method_has_no_args(). The fix should be the same for ticket #35175 👍

[Mariusz Felisiak <felisiak.mariusz@…>]

In e6fa74f:

Fixed #35179 -- Made admindocs detect positional/keyword-only arguments.