django super simple cart

views.py

from django.shortcuts import redirect
from django.shortcuts import get_object_or_404
from django.views.decorators.http import require_http_methods

def _get_products_in_cart(request):
  """
  Returns an array of dicts with the `product` and `quantity`
  as the two keys
  """
  cart = request.session.get('cart', {})
  
  products = Product.objects.in_bulk(cart.keys())
  return [
    {
      "product": products[product_id],
      "quantity": quantity
    } for product_id, quantity in cart.items()
  ]

def cart_page(request):
  products = _get_products_in_cart(request)
  
  # you can access product.quantity to see how many products are in the cart
  c = {
    "cart_products": products
  }
  return render(request, "cart.html", context=c)

@require_http_methods(["POST"])
def add_to_cart(request):
  
  product_id = request.POST.get("product_id")
  quantity = request.POST.get("quantity",1)
  
  product = get_object_or_404(Product, pk=product_id)
  cart = request.session.get('cart', {})
  cart[product.pk] = quantity
  request.session['cart'] = cart
  
  return redirect(...) # redirect back to previous page or product page