Django count() method : stop creating duplicate data in database

 @action(detail=False, methods=['post'], url_name='新增字典')
    def add(self, request):
        value = request.data["value"]
        status = True
        message = "创建成功"
        data = {"data": {}}
        if value != "":
            count = Dictionary.objects.filter(value=value).count()
            if count == 0:
                serializer = self.get_serializer(data=request.data)
                serializer.is_valid(raise_exception=True)
                self.perform_create(serializer)
                headers = self.get_success_headers(serializer.data)
                data = serializer.data
            else:
                status = False
                message = "重复的value值"
        else:
            status = False
            message = "传入value值为空"
        return getResponse(Response(data), message=message, status=status, success=status)