drf anon throttle with dot authorization grant type client_credentials caused request.user is None

[ViokingTung]

enviroment

Django==4.0.6
djangorestframework==3.13.1
django-oauth-toolkit==2.1.0

'DEFAULT_THROTTLE_RATES': {
	'anon': '100/day',
}

reproduce steps

1. authorized by client_credentials

2. request api by token,this caused errors:

   Traceback (most recent call last):
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/core/handlers/exception.py", line 55, in inner
       response = get_response(request)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/core/handlers/base.py", line 197, in _get_response
       response = wrapped_callback(request, *callback_args, **callback_kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
       return view_func(*args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/viewsets.py", line 125, in view
       return self.dispatch(request, *args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 509, in dispatch
       response = self.handle_exception(exc)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 469, in handle_exception
       self.raise_uncaught_exception(exc)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception
       raise exc
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 497, in dispatch
       self.initial(request, *args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 416, in initial
       self.check_throttles(request)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 359, in check_throttles
       if not throttle.allow_request(request, self):
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/throttling.py", line 119, in allow_request
       self.key = self.get_cache_key(request, view)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/throttling.py", line 174, in get_cache_key
       if request.user.is_authenticated:
   AttributeError: 'NoneType' object has no attribute 'is_authenticated'
   Internal Server Error: /ai/vehicle_det/
   Traceback (most recent call last):
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/core/handlers/exception.py", line 55, in inner
       response = get_response(request)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/core/handlers/base.py", line 197, in _get_response
       response = wrapped_callback(request, *callback_args, **callback_kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
       return view_func(*args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/viewsets.py", line 125, in view
       return self.dispatch(request, *args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 509, in dispatch
       response = self.handle_exception(exc)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 469, in handle_exception
       self.raise_uncaught_exception(exc)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception
       raise exc
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 497, in dispatch
       self.initial(request, *args, **kwargs)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 416, in initial
       self.check_throttles(request)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/views.py", line 359, in check_throttles
       if not throttle.allow_request(request, self):
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/throttling.py", line 119, in allow_request
       self.key = self.get_cache_key(request, view)
     File "/home/vioking/software/miniconda3/envs/gsunisAiOpen/lib/python3.9/site-packages/rest_framework/throttling.py", line 174, in get_cache_key
       if request.user.is_authenticated:
   AttributeError: 'NoneType' object has no attribute 'is_authenticated'

3. my ideas: those error beacause i authorized by client_credentials, the authorized info don`t include user info, if i i authorized by password, it work well. now i wanne authorizing by client_credentials and throttle anon user, have any idea? thanks.

[ViokingTung]

Fix error in throttling when request.user is None (https://github.com/encode/django-rest-framework/pull/8370[)](https://github.com/encode/django-rest-framework/commit/129890ab1bbbba2deb96b8e30675dfb1060d7615)

this error fixed.