Comprehensions or Loops?

Comprehension.py

    def get(self, request):

        return {
            "rooms": [
                {attrName: attrVal for attrName, attrVal in model_to_dict(x).items()
                    if attrName in RoomView.ROOM_PUBLIC_FIELDS}
                for x in Room.objects.all()
            ]
        }

Function.py

    # Only these fields will be returned by API calls
    ROOM_PUBLIC_FIELDS = [
        'id',
        'name'
    ]

    @staticmethod
    def filter_room_fields(room_obj):
        return {attrName: attrVal for attrName, attrVal in model_to_dict(room_obj).items()
                if attrName in RoomView.ROOM_PUBLIC_FIELDS}

    @json
    def get(self, request, room_id=None):

        if room_id:
            return RoomView.filter_room_fields(Room.objects.get(id=room_id))
        else:
            return {
                "rooms": [RoomView.filter_room_fields(room_obj) for room_obj in Room.objects.all()]
            }

Loops.py

    def get(self, request):

        result = {"rooms": []}

        for current_room in Room.objects.all():

            current_room_data = {}

            for attrName, attrVal in model_to_dict(current_room).items():

                if attrName in RoomView.ROOM_PUBLIC_FIELDS:
                    current_room_data[attrName] = attrVal

            result["rooms"].append(current_room_data)

        return result