Django: 'SessionStore' object has no attribute 'session'

Question

I'm trying to built an E-commerce following a tutorial on Udemy. I'm on the chapter on how to build the cart functionality (how to add items, see total cost and quantity).

However, I'm having troubles adding products to cart.

AttributeError at /cart/add/4/ 'SessionStore' object has no attribute 'session' Request Method: GET
Request URL: http://127.0.0.1:8000/cart/add/4/
Django Version: 2.1.3
Exception Type: AttributeError
Exception Value:
'SessionStore' object has no attribute 'session'
Exception Location: /home/ogonzales/Escritorio/web_proyects/perfectcushion/cart/views.py in _card_id, line 10
Python Executable: /home/ogonzales/Escritorio/projects_envs/perfectcushion_env/bin/python
Python Version: 3.6.7
Python Path:
['/home/ogonzales/Escritorio/web_proyects/perfectcushion', '/home/ogonzales/Escritorio/pycharm/helpers/pycharm', '/home/ogonzales/Escritorio/web_proyects/perfectcushion', '/usr/lib/python36.zip', '/usr/lib/python3.6', '/usr/lib/python3.6/lib-dynload', '/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages', '/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages/setuptools-39.1.0-py3.6.egg', '/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages/pip-10.0.1-py3.6.egg'] Server time: Sun, 2 Dec 2018 03:17:34 +0000

views.py:

from django.shortcuts import render, redirect
from shop.models import Product
from .models import Cart, CartItem
from django.core.exceptions import ObjectDoesNotExist


# Create your views here.

def _card_id(request):
    cart = request.session.session.key
    if not cart:
        cart = request.session.create()
        return cart


def add_cart(request, product_id):
    product = Product.objects.get(id = product_id)
    try:
        cart = Cart.objects.get(cart_id = _card_id(request))
    except Cart.DoesNotExist:
        cart = Cart.objects.create(
            cart_id = _card_id(request)
        )

        cart.save()
    try:
        cart_item = CartItem.objects.get(product = product, cart = cart)
        cart_item.quantity += 1
        cart_item.save()
    except CartItem.DoesNotExist:
        cart_item = CartItem.objects.create(
            product = product,
            quantity= 1,
            cart = cart,
        )
        cart_item.save()
    return redirect('cart:cart_detail')


def cart_detail(request, total = 0, counter = 0, cart_items = None):
    try:
        cart = Cart.objects.get(cart_id = _card_id(request))
        cart_items =  CartItem.objects.filter(cart = cart, active=True)

        for cart_item in cart_items:
            total += (cart_item.product.price * cart_item.quantity)
            counter += cart_item.quantity
    except ObjectDoesNotExist:
        pass

    return render(request, 'cart.html', dict(cart_items = cart_items, total = total, counter = counter))

models.py

from django.db import models
from shop.models import Product

# Create your models here.

class Cart(models.Model):
    cart_id = models.CharField(max_length=250, blank=True)
    date_added = models.DateField(auto_now_add=True)

    class Meta:
        db_table = 'Cart'
        ordering = ['date_added']

    def __str__(self):
        return self.cart_id


class CartItem(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    cart = models.ForeignKey(Cart, on_delete=models.CASCADE)
    quantity = models.IntegerField()
    active = models.BooleanField(default=True)
    class Meta:
        db_table = 'CartItem'

    def sub_total(self):
        return self.product.price * self.quantity

    def __str__(self):
        return self.product

Traceback:

Environment:


Request Method: GET
Request URL: http://127.0.0.1:8000/cart/add/4/

Django Version: 2.1.3
Python Version: 3.6.7
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'shop',
 'cart']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback:

File "/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "/home/ogonzales/Escritorio/projects_envs/perfectcushion_env/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/ogonzales/Escritorio/web_proyects/perfectcushion/cart/views.py" in add_cart
  19.         cart = Cart.objects.get(cart_id = _card_id(request))

File "/home/ogonzales/Escritorio/web_proyects/perfectcushion/cart/views.py" in _card_id
  10.     cart = request.session.session.key

Exception Type: AttributeError at /cart/add/4/
Exception Value: 'SessionStore' object has no attribute 'session'

Answer 1

Instead of cart = request.session.session.key use cart = request.session.session_key