How to display the page?

Question

Django

Hello.

cart/views.py

...
@require_POST
def cart_add(request, product_id, product_slug):
    cart = Cart(request)
    product = get_object_or_404(Product, id=product_id, slug = product_slug)
    form = CartAddProductForm(request.POST)
    if form.is_valid():
        cd = form.cleaned_data
        cart.add(product=product,
                 quantity=cd['quantity'],
                 update_quantity=cd['update'])
    return redirect('cart:cart_detail' )

def cart_remove(request, product_id, product_slug):
    
    cart = Cart(request)
    product = get_object_or_404(Product, id=product_id, slug = product_slug)
    cart.remove(product)
    return redirect('cart:cart_detail')

def cart_detail(request,product_id, product_slug,category_slug=None):
    product = get_object_or_404(Product, id=product_id, slug = product_slug)
    category = None
    categories = Category.objects.all()
    if category_slug:
        category = get_object_or_404(Category, slug=category_slug)
    cart = Cart(request)
    for item in cart:
        item['update_quantity_form'] = CartAddProductForm(initial={'quantity': item['quantity'],
                                                                   'update': True})
    coupon_apply_form = CouponApplyForm()
    return render(request, 'cart/detail.html', {'cart': cart,'category': category,'categories': categories,'coupon_apply_form':coupon_apply_form, 'product': product},id=product_id, slug = product_slug)

cart/urls.py

from django.conf.urls import url
from . import views


urlpatterns = [
    url(r'^$', views.cart_detail, name='cart_detail'),
    url(r'^add/(?P<product_id>\d+)(?P<product_slug>[-\w]+)/$', views.cart_add, name='cart_add'),
    url(r'^remove/(?P<product_id>\d+)/$', views.cart_remove, name='cart_remove'),
]

cart/detail.html

{% extends "app/layout.html" %}
{% load static %}



{% block content %}
 <table class="table-shopping-cart">
                <tr class="table_head">
                  <th class="column-1">Продукт</th>
                  <th class="column-2"></th>
                  <th class="column-3">Цена за шт</th>
                  <th class="column-4">Кол-во</th>
                  <th class="column-5">Итог</th>
                                    <th class="column-6">Удалить</th>
                </tr>
                                {% for item in cart  %}
                                    {% with product=item.product %}
                <tr class="table_row">
                  <td class="column-1">
                    <div class="how-itemcart1">
                      <a href="{{ product.get_absolute_url }}">
                      <img src="{% if product.image1 %}{{ product.image1.url }}{% else %}{% static 'content/no_image.png' %}{% endif %}">
                                            </a>
                    </div>
                  </td>
                  <td class="column-2">{{ product.name }}</td>
                  <td class="column-3">{{ item.price }} руб.</td>
                  <td class="column-4">
                    {{item.quantity}}
                  </td>
                  <td class="column-5">{{ item.total_price }} руб.   </td>
                                    <td class="column-6" ><a href="{% url 'cart:cart_remove' product.id product.slug %}">Удалить</a></td>
                </tr>
                                {% endwith %}
                                {% endfor %}
                
              
{% endblock %}

cart.py

from decimal import Decimal
import django
from django.conf import settings
from shop.models import Product
from coupons.models import Coupon

class Cart(object):

    def __init__(self, request):
        
        self.session = request.session
        cart = self.session.get(settings.CART_SESSION_ID)
        if not cart:
            # сохраняем ПУСТУЮ корзину в сессии
            cart = self.session[settings.CART_SESSION_ID] = {}
        self.cart = cart
        self.coupon_id = self.session.get('coupon_id')

    def __iter__(self):
        
        product_ids = self.cart.keys()
        # получаем товары и добавляем их в корзину
        products = Product.objects.filter(id__in=product_ids)

        cart = self.cart.copy()
        for product in products:
            cart[str(product.id)]['product'] = product

        for item in cart.values():
            item['price'] = Decimal(item['price'])
            item['total_price'] = item['price'] * item['quantity']
            yield item
    
    def __len__(self):
        
        return sum(item['quantity'] for item in self.cart.values())

    def add(self, product, quantity=1, update_quantity=True): # 22 10 2020 
       
        Добавляем товар в корзину или обновляем его количество.
        
        product_id = str(product.id)
        if product_id not in self.cart:
            self.cart[product_id] = {'quantity': 0,
                                      'price': str(product.price)}
        if update_quantity:
            self.cart[product_id]['quantity'] = quantity
        else:
            self.cart[product_id]['quantity'] += quantity
        self.save()

    def save(self):
        # сохраняем товар
        self.session.modified = True

    def remove(self, product):
        
        product_id = str(product.id)
        if product_id in self.cart:
            del self.cart[product_id]
            self.save()

    def get_total_price(self):
        # получаем общую стоимость
        return sum(Decimal(item['price']) * item['quantity'] for item in self.cart.values())

    @property
    def coupon(self):
        if self.coupon_id:
            return Coupon.objects.get(id=self.coupon_id)
        return None

    def get_discount(self):
        if self.coupon:
            return (self.coupon.discount / Decimal('100')) * self.get_total_price()
        return Decimal('0')

    def get_total_price_after_discount(self):
        return self.get_total_price() - self.get_discount()

    def clear(self):
        
        del self.session[settings.CART_SESSION_ID]
        self.save()

Main app/urls.py

urlpatterns = [
   
    ...
    url(r'^orders/', include('shop.urls', namespace='shop1')),
    url(r'^goods/', include('shop.urls',  namespace='shop')),
    url(r'^cart/', include('cart.urls', namespace='cart')),
    url(r'^contact$', app.views.contact, name='contact'),
    ...
  
<b>Приложение shop</b>

<spoiler title="shop/views.py"><code>
...
from django.shortcuts import render, get_object_or_404,redirect
def product_list(request, category_slug=None):
    category = None
    categories = Category.objects.all()
    products = Product.objects.filter(available=True)
    if category_slug:
        category = get_object_or_404(Category, slug=category_slug)
        products = products.filter(category=category)
    return render(request,
                  'shop/product/list.html',
                  {'category': category,
                   'categories': categories,
                   'products': products})



def product_detail(request, id, slug,category_slug=None):
    category = None
    categories = Category.objects.all()
    if category_slug:
        category = get_object_or_404(Category, slug=category_slug)
    product = get_object_or_404(Product,
                                id=id,
                                slug=slug,
                                available=True)
    cart_product_form = CartAddProductForm()


  
    assert isinstance(request, HttpRequest)
    return render(request, 'shop/product/detail.html', {'reviews':reviews,'product': product,'form':form,'cart_product_form': cart_product_form,'category': category,'categories': categories,})
                                                        



def order_create(request,product_id,product_slug):
    cart = Cart(request)
    product = get_object_or_404(Product,
                                id=product_id,
                                slug=product_slug,
                                )
    if request.method == 'POST':
        form = OrderCreateForm(request.POST)
        if form.is_valid():
            order = form.save(commit=False)
            
            order.nickname = request.user
            order.product = product
            order.save()
            for item in cart:
                Order.objects.create(
                                         product=item['product'],
                                         price=item['price'],
                                         quantity=item['quantity'])
           
            # очистка корзины
            cart.clear()
            return render(request, 'orders/order/created.html',
                          {'order': order})
    else:
        form = OrderCreateForm()
    return render(request, 'orders/order/create.html', 
                  {'cart': cart, 'form': form, 'product':product})


</code></spoiler>

<img src="https://habrastorage.org/webt/5f/ce/15/5fce159050df8277280844.png" alt="image"/>
<img src="https://habrastorage.org/webt/5f/ce/16/5fce1649b88ec058912027.png" alt="image"/>
 <b>Кажется нужно прописать что-то в cart/detil.html, но что?</b>

Answer 1

translate the error, the reason is clearly indicated there