views,py

# serverapi\view.py
from rest_framework.decorators import api_view
from django.http import JsonResponse

@api_view(['PUT'])
def updateWishlist(request):
    data = json.loads(request.body)
    productID = data['productID']
    action = data['action']
    print('ProductID:', productID)
    print('Action:   ', action)

    if request.user.is_authenticated:
        customer = request.user
        wishList, created = Wishlist.objects.get_or_create(customer=customer)

        if action == 'add':
            wishList.add_item(productID)
            return JsonResponse({'wishlistItemQuantity': wishList.get_wishlist_quantity})

        elif action == 'add_to_cart':
            return JsonResponse({'cartItemQuantity': wishList.add_to_cart(productID),
                                'wishlistItemQuantity': wishList.get_wishlist_quantity})