def get(self): try: from_date, to_date = self._get_booking_date() count_booking_days = (to_date - from_date).days except ValueError as e: self.set_response(dict(message=str(e)), status=400) return queryset = Room.find_available_between_dates(from_date.isoformat(), to_date.isoformat()) rooms = map(lambda room: model_to_dict( room, append_attrs=self._prepare_addition_attrs(room, count_booking_days) ), queryset) self.set_response(dict(rooms=rooms))