Completing an order?

Question

Django

Please tell me how to make the shopping cart empty when buying a product. And there is also a problem that without re-authorization I can’t make more than 1 order (throws to complete the purchase of the last product)
The essence of the work: after pressing the checkout button, the product is sent to orders and the next field is filled in the address, after the address the final form pops out, which indicates how much and what they bought (here they throw it at the next order)
a basket of goods:

{% extends "base.html" %}


{% block content %}
<h1>Cart</h1>

{% if cart.products.exists %}
<table class="table cart-table">
  <thead>
    <tr>
      <th>#</th>
      <th>Название: </th>
      <th>Цена: </th>
    </tr>
  </thead>
  <tbody class='cart-body'>
    {% for product in cart.products.all %}
    <tr class='cart-product'>
      <th scope="row">{{ forloop.counter }}</th>
      <td><a href='{{ product.get_absolute_url }}'>{{ product.title }}</a> 
        {% include 'carts/snippets/remove-product.html' with product_id=product.id %}
      </td>
      <td>{{ product.price }}</td>
    </tr>
    {% endfor %}
    <tr>
      <td colspan="2"></td>
      <td><b>Subtotal</b> $<span class='cart-subtotal'>{{ cart.subtotal }}</span></td>
    </tr>
    <tr>
      <td colspan="2"></td>
      <td><b>Total</b> $<span class='cart-total'>{{ cart.total }}</span></td>
    </tr>
    <tr>
      <td colspan="2"></td>
      <td><a class='btn btn-lg btn-success' href='{% url "cart:checkout" %}'>Checkout</a></td>
    </tr>

  </tbody>
</table>

<div class='cart-item-remove-form' style='display:none'>

    {% include 'carts/snippets/remove-product.html' %}
  </div>

{% else %}
<p class='lead'>Корзина пуста</p>
{% endif %}


{% endblock %}

URLs.py:

url(r'^$', cart_home, name='home'),
    url(r'^checkout/success/$', checkout_done_view, name='success'),
    url(r'^checkout/$', checkout_home, name='checkout'),
    url(r'^update/$', cart_update, name='update'),

views.py:

def checkout_home(request):
    cart_obj, cart_created = Cart.objects.new_or_get(request)
    order_obj = None
    if cart_created or cart_obj.products.count() == 0:
        return redirect("cart:home")

    login_form = LoginForm(request=request)
    guest_form = GuestForm(request=request)
    address_form = AddressCheckoutForm()
    # billing_address_id = request.session.get("billing_address_id", None)
    shipping_address_id = request.session.get("shipping_address_id", None)

    billing_profile, billing_profile_created = BillingProfile.objects.new_or_get(request)
    address_qs = None
    # has_card = False
    if billing_profile is not None:
        if request.user.is_authenticated():
            address_qs = Address.objects.filter(billing_profile=billing_profile)
        order_obj, order_obj_created = Order.objects.new_or_get(billing_profile, cart_obj)
        if shipping_address_id:
            order_obj.shipping_address = Address.objects.get(id=shipping_address_id)
            del request.session["shipping_address_id"]
        if shipping_address_id:
            order_obj.save()
        # has_card = billing_profile.has_card

    if request.method == "POST":
        "проверьте, что заказ выполнен"
        is_prepared = order_obj.check_done()
        if is_prepared:
            did_charge, crg_msg = billing_profile.charge(order_obj)
            if did_charge:
                order_obj.mark_paid()
                request.session['cart_items'] = 0
                del request.session['cart_id']
                if not billing_profile.user:
                    '''
                    is this the best spot?
                    '''
                    billing_profile.set_cards_inactive()
                return redirect("cart:success")
            else:
                print(crg_msg)
                return redirect("cart:checkout")
    context = {
        "object": order_obj,
        "billing_profile": billing_profile,
        "login_form": login_form,
        "guest_form": guest_form,
        "address_form": address_form,
        "address_qs": address_qs,
        # "has_card": has_card,
        "publish_key": STRIPE_PUB_KEY,
    }
    return render(request, "carts/checkout.html", context)

address form and order information output:

{% if not billing_profile %}
    <div class='row text-center'>
    <div class='col-12 col-md-6'>
        <p class='lead'>Вход</p>
        {% include 'accounts/snippets/form.html' with form=login_form next_url=request.build_absolute_uri %}
    </div>
    <div class='col-12 col-md-6'>
        Продолжить как Гость

        {% url "guest_register" as guest_register_url %}
        {% include 'accounts/snippets/form.html' with form=guest_form next_url=request.build_absolute_uri action_url=guest_register_url %}
    </div>

    </div>

{% else %}

        {% if not object.shipping_address %}

         <div class='row'>
            <div class='col-md-10'>
                <p class='lead'>Адрес доставки</p>
                <hr/>
            </div>

            <div class='col-md-5'>




                    {% url "checkout_address_create" as checkout_address_create %}
                    {% include 'addresses/form.html' with form=address_form next_url=request.build_absolute_uri action_url=checkout_address_create address_type='shipping' %}



             </div>
         <div class='col-md-5'>
            {% url 'checkout_address_reuse' as checkout_address_reuse %}
            {% include 'addresses/prev_addresses.html' with address_qs=address_qs next_url=request.build_absolute_uri address_type='shipping' action_url=checkout_address_reuse %}
            </div>
        </div>



        {% else %}

                <h1>Завершить Оформление Заказа</h1>
                <p>Детали карты: {% for product in object.cart.products.all %}{{ product }}{% if not forloop.last %}, {% endif %}{% endfor %}</p>
                <p>Адрес доставки: {{ object.shipping_address.get_address }}</p>
                <p>Платежный адрес: {{ object.shipping_address.get_address }}</p>
                <p>Способ оплаты: {{ billing_profile.default_card }} (<a href="{{ billing_profile.get_payment_method_url }}?next={{ request.build_absolute_uri }}">Change</a>)</p>
                <p>Корзина Всего: {{ object.cart.total }}</p>
                <p>Итог Доставки: {{ object.shipping_total }}</p>
                <p>Итог Заказа: {{ object.total }}</p>

                <form class='form' method='POST' action="">{% csrf_token %}
                    <button type='submit' class='btn btn-success'>Заказать</button>
                </form>


        {% endif %}
{% endif %}