Django rest framework model-less

views.py

from rest_framework import viewsets
from rest_framework.response import Response
from rest_framework import serializers
from rest_framework.authentication import SessionAuthentication, BasicAuthentication
from rest_framework.permissions import IsAuthenticated

class Cart(object):
    def __init__(self, **kwargs):
        fields = ('id', 'price', 'quantity', 'total')
        for field in fields:
            setattr(self, field, kwargs.get(field, None))


class CartSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    price = serializers.CharField(max_length=256)
    quantity = serializers.CharField(max_length=256)
    total =  serializers.CharField(max_length=256)

    def create(self, validated_data):
        return Cart(id=None, **validated_data)

    def update(self, instance, validated_data):
        for field, value in validated_data.items():
            setattr(instance, field, value)
        return instance
        

class CartView(viewsets.ViewSet):
    serializer_class = CartSerializer
    authentication_classes = (SessionAuthentication, BasicAuthentication)
    permission_classes = (IsAuthenticated,)

    def list(self, request):
        serializer = CartSerializer(
            instance={}, many=True)
        return Response(serializer.data)