如何标记符合购物车价格规则的产品

# models.py
from django.db import models

class Product(models.Model):
    name = models.CharField(max_length=100)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    is_discounted = models.BooleanField(default=False)

class Cart(models.Model):
    user = models.ForeignKey('auth.User', on_delete=models.CASCADE)
    products = models.ManyToManyField(Product)

# views.py
from django.shortcuts import render, get_object_or_404
from .models import Cart, Product

def add_to_cart(request, product_id):
    cart, created = Cart.objects.get_or_create(user=request.user)
    product = get_object_or_404(Product, id=product_id)
    
    # 检查价格规则
    if product.price > 100:  # 示例规则：价格大于100的商品打折
        product.is_discounted = True
        product.save()
    
    cart.products.add(product)
    return render(request, 'cart.html', {'cart': cart})

# cart.html
{% for product in cart.products.all %}
    <div>
        <h3>{{ product.name }}</h3>
        <p>Price: {{ product.price }}</p>
        {% if product.is_discounted %}
            <p>Discounted!</p>
        {% endif %}
    </div>
{% endfor %}