# Serializers class ProductPriceSerializer(serializers.ModelSerializer): product = ProductSerializer(read_only=True) data_type = serializers.SerializerMethodField() @classmethod def get_data_type(cls, obj): if hasattr(obj, 'price_before') and obj.price_before: return 'price' else: return 'new' class Meta: model = ProductPrice fields = '__all__'