如何在ManyToMany Django中获取数据并在view.py中渲染

from django.db import models

class Category(models.Model):
    name = models.CharField(max_length=100)

class Product(models.Model):
    name = models.CharField(max_length=100)
    categories = models.ManyToManyField(Category)

from django.shortcuts import render
from .models import Product

def product_detail(request, product_id):
    product = Product.objects.get(id=product_id)
    categories = product.categories.all()
    return render(request, 'product_detail.html', {'product': product, 'categories': categories})

<h1>{{ product.name }}</h1>
<ul>
    {% for category in categories %}
        <li>{{ category.name }}</li>
    {% endfor %}
</ul>