Django -如何在会话中保存购物车项目

INSTALLED_APPS = [
    ...
    'django.contrib.sessions',
    ...
]

MIDDLEWARE = [
    ...
    'django.contrib.sessions.middleware.SessionMiddleware',
    ...
]

from django.shortcuts import render, redirect

def add_to_cart(request, product_id):
    # 获取购物车项目
    cart = request.session.get('cart', {})
    
    # 更新购物车项目
    if product_id in cart:
        cart[product_id] += 1
    else:
        cart[product_id] = 1
    
    # 保存购物车项目到会话中
    request.session['cart'] = cart
    
    return redirect('cart')

def remove_from_cart(request, product_id):
    # 获取购物车项目
    cart = request.session.get('cart', {})
    
    # 从购物车中删除商品
    if product_id in cart:
        del cart[product_id]
    
    # 保存购物车项目到会话中
    request.session['cart'] = cart
    
    return redirect('cart')

def update_cart(request, product_id):
    # 获取购物车项目
    cart = request.session.get('cart', {})
    
    # 更新购物车项目
    if product_id in cart:
        cart[product_id] = request.POST.get('quantity')
    
    # 保存购物车项目到会话中
    request.session['cart'] = cart
    
    return redirect('cart')

from django.shortcuts import render

def view_cart(request):
    # 获取购物车项目
    cart = request.session.get('cart', {})
    
    # 根据购物车项目获取商品信息
    products = []
    for product_id, quantity in cart.items():
        product = Product.objects.get(id=product_id)
        products.append({
            'product': product,
            'quantity': quantity
        })
    
    # 渲染购物车模板
    return render(request, 'cart.html', {'products': products})