Django rest framework 基于url中kwarg的django过滤器查询集

我试图根据url中的kwarg筛选queryset。 我的url类似于：

http://localhost:8000/notification/all/?type="workflow"

我想筛选url中是否存在类型参数

class NotificationList(generics.ListAPIView):
    model = Notification
    serializer_class = NotificationSerializer

    def get_queryset(self):
        queryset =  Notification.objects.filter(created_for=self.request.user)[:int(settings.NOTIFICATION_PAGE_SIZE)]
        type_param = self.request.query_params.get('type')
        last = self.request.query_params.get('last')
        print("TYPE PARAm", type_param)

        if str(type_param)=="workflow":
                print("TRUEEEEEEEEEEEEEeeeee")
                queryset = Notification.objects.filter(created_for=self.request.user).instance_of(WorkflowNotification)

        if last:
            last_notification_created_on = Notification.objects.get(id=last)
            queryset = queryset.filter(created_on__lt=last_notification_created_on)


        return queryset

目前，即使我将url中的类型指定为工作流，它也没有进入if条件。可能有什么问题？

请应用此选项

从url中删除

如果类型不是工作流，只需引发错误

if type == 'workflow':
  print("TRUEEEEEEEEEEEEEeeeee")
  queryset = ....
else:
    from rest_framework.exceptions import NotFound
    raise NotFound(detail="no notifications", code=404) 

---

我想返回一个错误，如：否notifications@MohitHarshan，请看一看。