Question

我想计算模板中购物车的总数：这是我的带有产品表的模板。我试图在购物车方法中使用Generator表达式，但是它不起作用。有什么想法吗？

cart.html

<table>
    {% if not cart_list %}
        {{ "The cart is empty" }}
    {% else %}
        <tr>
            <th>Name</th>
            <th>Price</th>
        </tr>
        {% for product in cart_list %}
        <tr>
          <td>{{ product.name }}</td>
          <td>${{ product.price }}</td>
        </tr>
        {% endfor %}
        <tr>
          <td>{{ Total }}</td>
          <td>{{ total_prices }}</td>
        </tr>
    {% endif %}
</table>

views.py

def cart(request):
  if request.method == 'GET':
    cart_list = Product.objects.filter(in_cart = True)
    total_prices = sum(product.price for product in cart_list)
    template_cart = loader.get_template('cart/cart.html')
    context = {'cart_list': cart_list}
    return HttpResponse(template_cart.render(context, request))

Answer 1

如果您希望total_prices在context中可见，请将template添加到def cart(request): if request.method == 'GET': ... total_prices = sum(product.price for product in cart_list) context = { 'cart_list': cart_list, 'total_prices': total_prices } return HttpResponse(template_cart.render(context, request))变量中。

from django.db.models import Sum

Product.objects.filter(in_cart=True).aggregate(Sum('price'))

# you will have something like this -> 34.35 is example
# {'price__sum': 34.35}

但是您可以尝试使用aggregate之类的东西。

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Django模板中的对象价格总和

1 个答案: