      """
      scope = 'user'
  
      def get_cache_key(self, request, view):
          if request.user.is_authenticated():
              ident = request.user.pk
          else:
              ident = self.get_ident(request)
  
          return self.cache_format % {
 
</s> remove         if request.user.is_authenticated():
 </s> add         if is_authenticated(request.user): </s> remove         if request.user.is_authenticated():
 </s> add         if is_authenticated(request.user): </s> remove         return request.user and request.user.is_authenticated()
 </s> add         return request.user and is_authenticated(request.user) </s> remove             request.user.is_authenticated()
 </s> add             is_authenticated(request.user) </s> remove             (request.user.is_authenticated() or not self.authenticated_users_only) and
 </s> add             (is_authenticated(request.user) or not self.authenticated_users_only) and
        if is_authenticated(request.user):
      """
      scope = 'user'
  
      def get_cache_key(self, request, view):
        if is_authenticated(request.user):
              ident = request.user.pk
          else:
              ident = self.get_ident(request)
  
          return self.cache_format % {
keep keep keep keep replace keep keep keep keep keep
 Access `request.user.is_authenticated` as property not method, under Django 1.10+ (#4358)

* For Django >=1.10 use user.is_authenticated, not user.is_authenticated() 
rest_framework/throttling.py