Bug with Views being nested partials

[Grégory Starck]

If you define a view v2 like this:

def view(request):
    pass

v1 = functools.partial(view)
v2 = functools.partial(v1)

then set v2 as the view for some url, then you'll get an attribute error if you try reverse() on it :

AttributeError: 'functools.partial' object has no attribute 'module'

  File "/home/gstarck/work/public/python/django-all/django/django/urls/base.py", line 91, in reverse
    return force_text(iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)))
  File "/home/gstarck/work/public/python/django-all/django/django/urls/resolvers.py", line 323, in _reverse_with_prefix
    self._populate()
  File "/home/gstarck/work/public/python/django-all/django/django/urls/resolvers.py", line 183, in _populate
    self._callback_strs.add(pattern.lookup_str)
  File "/home/gstarck/work/public/python/django-all/django/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/gstarck/work/public/python/django-all/django/django/urls/resolvers.py", line 141, in lookup_str
    return callback.__module__ + "." + callback.__class__.__name__
AttributeError: 'functools.partial' object has no attribute '__module__'

I have a patch / test case for this..

[Grégory Starck]

I've initially raised my concern here: ​https://github.com/django/django/pull/5578#discussion_r48514488

[Simon Charette]

Please check has patch when it is ready.

[Grégory Starck]

I have a test case as well as a patch.. should I submit that as PR ?

[Simon Charette]

Please do, make sure the PR also refers to this ticket: Fixed #26039 -- Unwrapped nested partials in URL reversal.

[Tim Graham]

​PR

[Tim Graham <timograham@…>]

In 9f9921e:

Fixed #26039 -- Unwrapped nested partials in URL reversal.

Prior to Python 3.5 nested partials need to be fully "unfolded"
to get the actual function.