                      'Use `.all()` or call `.get_queryset()` instead.'
                  )
              cls.queryset._fetch_all = force_evaluation
  
          view = super(APIView, cls).as_view(**initkwargs)
          view.cls = cls
          view.initkwargs = initkwargs
  
          # Note: session based authentication is explicitly CSRF validated,
          # all other authentication is CSRF exempt.
 
</s> remove class ForcedAuthentication(object):
 </s> add class ForcedAuthentication: </s> remove         class MockUser(object):
 </s> add         class MockUser: </s> remove         request = super(ViewSetMixin, self).initialize_request(request, *args, **kwargs)
 </s> add         request = super().initialize_request(request, *args, **kwargs) </s> remove         request = factory.patch('/{0}'.format(obj.pk), {'number_value': 101}, format='json')
 </s> add         request = factory.patch('/{}'.format(obj.pk), {'number_value': 101}, format='json') </s> remove from __future__ import unicode_literals

 </s> add 
        view = super().as_view(**initkwargs)
                      'Use `.all()` or call `.get_queryset()` instead.'
                  )
              cls.queryset._fetch_all = force_evaluation
  
        view = super().as_view(**initkwargs)
          view.cls = cls
          view.initkwargs = initkwargs
  
          # Note: session based authentication is explicitly CSRF validated,
          # all other authentication is CSRF exempt.
keep keep keep keep replace keep keep keep keep keep
 Dropped Python 2 compatibility. (#6615)

Thanks to Jon Dufresne (@jdufresne) for review.

Co-authored-by: Asif Saif Uddin <auvipy@gmail.com>
Co-authored-by: Rizwan Mansuri <Rizwan@webbyfox.com> 
rest_framework/views.py