Django 错误：\'dict\' 对象没有属性 \'availability\'

Question

我有一个购物车视图，我正在尝试检查添加到购物车的产品是否在列表中甚至有一项将 product.availability 设置为 False 并在模板中相应地工作，问题在于访问购物车中的产品可用性对象列表，那么我如何检查人们添加到购物车的产品的可用性？

PS我缩短了utils的代码，如果需要理解我会添加更多

模型

class Product(models.Model):
    availability = models.BooleanField()

实用程序

def cookieCart(request):
    try:
        cart = json.loads(request.COOKIES['cart'])
    except:
        cart = {}
    items = []
    for i in cart:
        try:
            product = Product.objects.get(id=i)
            item = {
                'product':{
                    'id':product.id,
                    'name':product.name,
                    'final_price':product.final_price,
                    'image_URL':product.image_URL,
                    'availability':product.availability,
                },
                    'quantity':cart[i]["quantity"],
                    'get_total':total,
                }
            items.append(item)
        except:
            pass

    return {"items": items}

def cartData(request):
    if request.user.is_authenticated:
        customer = request.user.customer
        order, created = Order.objects.get_or_create(customer=customer, complete=False)
        items = order.orderitem_set.all()
    else:
        cookieData = cookieCart(request)
        items = cookieData['items']
    return {'items':items}

意见

def cart(request):
    data = cartData(request)
    #products added to cart
    items = data['items']

    #Checking if even one product added to cart has availability set to False
    available = all(x.availability for x in items)

    context = {'items': items, 'available': available}

模板

<p>{{items.product.name}}</p>
{% if available %}
    <a href="#">Checkout</a>
{% else %}
    <p>Out of stock</p>
{% endif %}

追溯

Traceback (most recent call last):
  File "D:\test\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "D:\test\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "D:\test\shop\views.py", line 101, in cart
    available = all(x.availability for x in items)
  File "D:\test\shop\views.py", line 101, in <genexpr>
    available = all(x.availability for x in items)

Exception Type: AttributeError at /shop/cart
Exception Value: 'dict' object has no attribute 'availability'

Answer 1

它非常简单，在 cookieCart 函数中，您将附加到项目列表的字典，而不是 Product 对象。

改成：

def cookieCart(request):
    try:
        cart = json.loads(request.COOKIES['cart'])
    except:
        cart = {}
    items = []
    for i in cart:
        try:
            product = Product.objects.get(id=i)            
            items.append(product)
        except:
            pass

    return {"items": items}

Answer 2

在按 ID 过滤产品后，您应该简单地返回 QuerySet 的 Product 对象，而不是创建具有必要的 availability 属性的临时字典：

def cookieCart(request):
    try:
        cart = json.loads(request.COOKIES['cart'])
    except:
        cart = {}
    return {"items": Product.objects.filter(id__in=cart)}

Answer 3

这部分正在创建问题

def cookieCart(request):
    try:
        cart = json.loads(request.COOKIES['cart'])
    except:
        cart = {}
    items = []
    for i in cart:
        try:
            product = Product.objects.get(id=i)
            item = {
                'product':{
                    'id':product.id,
                    'name':product.name,
                    'final_price':product.final_price,
                    'image_URL':product.image_URL,
                    'availability':product.availability,
                },
                }
            items.append(item)
        except:
            pass

    return {"items": items} # here your items is like this {"items": [{'product':{'id':product.id,'name':product.name,'final_price':product.final_price,'image_URL':product.image_URL,'availability':product.availability}}]}

由于错误提示您从 COOKIES 中选择了项目

现在因为你循环为all(x.availability for x in items) x 看起来像 {price: {...}} 这是 dict 对象，这就是说 dict 对象没有属性可用性

要解决此问题，请像这样使用SimpleNameSpace

from types import SimpleNamespace

def cookieCart(request):
    try:
        cart = json.loads(request.COOKIES['cart'])
    except:
        cart = {}
    items = []
    for i in cart:
        try:
            product = Product.objects.get(id=i)
            item = SimpleNamespace(**{
                    'id':product.id,
                    'name':product.name,
                    'final_price':product.final_price,
                    'image_URL':product.image_URL,
                    'availability':product.availability,
                })
            items.append(item)
        except:
            pass

    return {"items": items}

对于优化方式 你可以检查@blhsing解决方案

Answer 4

该错误告诉您的是您正在尝试将 dict 项目作为属性访问。

这应该是：

available = all(x['availability'] for x in items)