id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
33351	path()/re_path() should raise a TypeError when kwargs is not a dict.	Keryn Knight	Pedro Schlickmann Mendes	"Apparently, however many years into using Django, I'm still capable of making a ""newbie"" mistake and getting confused. So perhaps other actual new users encounter similar, especially given the lack of typing specifiers.

I defined a URL like so:
{{{
urlpatterns = [
    path(""path/to/thing"", MyView.as_view(), ""my_view""),
]
}}}

which ... well, you either spot the issue immediately or you don't, and end up with the following. If you try and `resolve()` the path (eg: by making a request in your browser), you'll get something like:
{{{
In [3]: resolve(""/path/to/thing"")
~/Code/django/django/urls/base.py in resolve(path, urlconf)
     22     if urlconf is None:
     23         urlconf = get_urlconf()
---> 24     return get_resolver(urlconf).resolve(path)
     25
     26

~/Code/django/django/urls/resolvers.py in resolve(self, path)
    586             for pattern in self.url_patterns:
    587                 try:
--> 588                     sub_match = pattern.resolve(new_path)
    589                 except Resolver404 as e:
    590                     self._extend_tried(tried, pattern, e.args[0].get('tried'))

~/Code/django/django/urls/resolvers.py in resolve(self, path)
    388             new_path, args, kwargs = match
    389             # Pass any extra_kwargs as **kwargs.
--> 390             kwargs.update(self.default_args)
    391             return ResolverMatch(self.callback, args, kwargs, self.pattern.name, route=str(self.pattern))
    392

ValueError: dictionary update sequence element #0 has length 1; 2 is required
}}}

The crux of the issue being that I ''meant'' to give the URL a name, and it's a super unfortunate history that `kwargs` comes ''before'' the `name` argument (because nearly everyone gives a URL a name, but passing static kwargs is ''comparatively'' infrequent). So what's actually happened is that `kwargs = ""my_view""` and eventually `self.default_args = ""my_view""`.

If I update to `path(""path/to/thing"", MyView.as_view(), ""my_view"", name=""my_view"")`, leaving the type incorrect, I can get the following error via reverse, too:
{{{
In [4]: reverse(""my_view"")
~/Code/django/django/urls/base.py in reverse(viewname, urlconf, args, kwargs, current_app)
     84             resolver = get_ns_resolver(ns_pattern, resolver, tuple(ns_converters.items()))
     85
---> 86     return resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
     87
     88

~/Code/django/django/urls/resolvers.py in _reverse_with_prefix(self, lookup_view, _prefix, *args, **kwargs)
    669                     if set(kwargs).symmetric_difference(params).difference(defaults):
    670                         continue
--> 671                     if any(kwargs.get(k, v) != v for k, v in defaults.items()):
    672                         continue
    673                     candidate_subs = kwargs

AttributeError: 'str' object has no attribute 'items'
}}}

Both of these suggest that either there should be a type-guard in `_path` to assert it's ''dict-ish'' (if not `None`), or a system check on `URLPattern` to raise a friendly message. Well, they actually continue to suggest to me that everything after the `view` argument should be keyword-only, or that kwargs should come later, but I suspect those to be a harder sell ;)

This is specifically around the `kwargs`, but it doesn't look like there's any guarding on the `name` either, and I feel like a name of `{'test': 'test'}` (i.e. accidentally swapped both positionals) is likely to bite & cause an issue somewhere."	Cleanup/optimization	closed	Core (URLs)	dev	Normal	fixed	path _path URLPattern check	Egor R Pedro Schlickmann Mendes	Ready for checkin	1	0	0	0	1	0