корзина добавлена, но при оформлении заказа взимается дважды

Question

У меня возникли проблемы с оплатой в корзине. Когда я оформляю заказ на один товар, он проверяет два заказа (независимо от того, сколько товаров у меня в корзине). Вот функция, которую я должен создать корзину в сеансе и ошибка:

from django.shortcuts import get_object_or_404
from tour_store.models import Destinations

def cart_contents(request):
    """
    Ensures that the cart contents are available when rendering
    every page
    """
    cart = request.session.get('cart', {})

    cart_items = []
    total = 0
    destination_count = 0

    for id, quantity in cart.items():
        destination = get_object_or_404(Destinations, pk=id)
        total += quantity * destination.price
        destination_count += quantity
        cart_items.append({'id': id, 'quantity': quantity, 'destination': destination})
    #cart_item will loop into the cart.
    print(cart_items)
    print(destination_count)
    print(cart)
    return {'cart_items': cart_items, 'total': total, 'destination_count': destination_count}

===== ОБОЛОЧКА ============== *

{'1': 1} << NORMAL CART ADDED
[11/Mar/2020 16:27:38] "GET /chekout/ HTTP/1.1" 200 12919
{'1': 1}. << DOUBLE THE CART AND CHARGE
{'1': 1}
[11/Mar/2020 16:28:59] "POST /chekout/ HTTP/1.1" 302 0
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 54962)
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/socketserver.py", line 650, in process_request_thread
    self.finish_request(request, client_address)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/socketserver.py", line 360, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/socketserver.py", line 720, in __init__
    self.handle()
  File "/Users/macbook/software_projects/tour_project/venv/lib/python3.8/site-packages/django/core/servers/basehttp.py", line 174, in handle
    self.handle_one_request()
  File "/Users/macbook/software_projects/tour_project/venv/lib/python3.8/site-packages/django/core/servers/basehttp.py", line 182, in handle_one_request
    self.raw_requestline = self.rfile.readline(65537)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/socket.py", line 669, in readinto
    return self._sock.recv_into(b)
ConnectionResetError: [Errno 54] Connection reset by peer
----------------------------------------
[]
0
{}
[11/Mar/2020 16:28:59] "GET /store/ HTTP/1.1" 200 8604