old_contents: from django.shortcuts import render
  from rest_framework import generics
  from .models import Item
  from .serializers import ItemSerializer
  # Create your views here.
  
  class ItemList(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = ItemSerializer
  
  class ItemDetail(generics.RetrieveAPIView):
      queryset = Item.objects.all()
      serializer_class = ItemSerializer
new_contents: from django.shortcuts import render
  from rest_framework import generics
  from rest_framework import permissions
  from .models import Item
  from .serializers import ItemSerializer
  from .serializers import BrandSerializer
  from .serializers import CategorySerializer
  from .serializers import BaseItemSerializer
  from .permissions import IsOwnerOrReadOnly
  # Create your views here.
  
  class BrandList(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = BrandSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class BrandDetail(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = BrandSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class CategoryList(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = CategorySerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class CategoryDetail(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = CategorySerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class BaseItemList(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = BaseItemSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class BaseItemDetail(generics.RetrieveAPIView):
      queryset = Item.objects.all()
      serializer_class = BaseItemSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class ItemList(generics.ListCreateAPIView):
      queryset = Item.objects.all()
      serializer_class = ItemSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
  
  class ItemDetail(generics.RetrieveAPIView):
      queryset = Item.objects.all()
      serializer_class = ItemSerializer
      permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                        IsOwnerOrReadOnly,)
  
      def perform_create(self, serializer):
          serializer.save(owner=self.request.user)
subject: add more APIs, save point before refactoring to ViewSet