Building a Modern E-commerce Platform with Django

# Smart shopping cart that persists across sessions
class Cart:
    def __init__(self, request):
        self.session = request.session
        cart = self.session.get(settings.CART_SESSION_ID)
        if not cart:
            cart = self.session[settings.CART_SESSION_ID] = {}
        self.cart = cart

# Custom admin actions for better store management
@admin.action(description='Export to CSV')
def export_to_csv(modeladmin, request, queryset):
    # Export orders to CSV for accounting
    response = HttpResponse(content_type='text/csv')
    response['Content-Disposition'] = 'attachment; filename="orders.csv"'
    writer = csv.writer(response)
    # ... CSV generation logic

# Django's elegant URL routing
urlpatterns = [
    path('', views.product_list, name='product_list'),
    path('<slug:category_slug>/', views.product_list, name='product_list_by_category'),
    path('<int:id>/<slug:slug>/', views.product_detail, name='product_detail'),
]

1# Models: Your data structure
2class Product(models.Model):
3    category = models.ForeignKey(Category, on_delete=models.CASCADE)
4    name = models.CharField(max_length=200)
5    price = models.DecimalField(max_digits=10, decimal_places=2)
6    available = models.BooleanField(default=True)
7    created = models.DateTimeField(auto_now_add=True)
8
9# Views: Your business logic  
10def product_list(request, category_slug=None):
11    category = None
12    categories = Category.objects.all()
13    products = Product.objects.filter(available=True)
14    
15    if category_slug:
16        category = get_object_or_404(Category, slug=category_slug)
17        products = products.filter(category=category)
18    
19    return render(request, 'shop/product/list.html', {
20        'category': category,
21        'categories': categories,
22        'products': products
23    })

1# Dynamic category filtering with SEO-friendly URLs
2class Category(models.Model):
3    name = models.CharField(max_length=200, db_index=True)
4    slug = models.SlugField(max_length=200, unique=True)
5    
6    class Meta:
7        ordering = ('name',)
8        verbose_name = 'category'
9        verbose_name_plural = 'categories'
10    
11    def get_absolute_url(self):
12        return reverse('shop:product_list_by_category', args=[self.slug])

1# Cart with advanced features
2class Cart:
3    def add(self, product, quantity=1, override_quantity=False):
4        product_id = str(product.id)
5        
6        if product_id not in self.cart:
7            self.cart[product_id] = {
8                'quantity': 0,
9                'price': str(product.price)
10            }
11        
12        if override_quantity:
13            self.cart[product_id]['quantity'] = quantity
14        else:
15            self.cart[product_id]['quantity'] += quantity
16            
17        self.save()
18
19    def get_total_price(self):
20        return sum(Decimal(item['price']) * item['quantity'] 
21                  for item in self.cart.values())

1# Secure order creation with validation
2@transaction.atomic
3def order_create(request):
4    cart = Cart(request)
5    if request.method == 'POST':
6        form = OrderCreateForm(request.POST)
7        if form.is_valid():
8            order = form.save(commit=False)
9            if cart.coupon:
10                order.coupon = cart.coupon
11                order.discount = cart.coupon.discount
12            order.save()
13            
14            # Create order items
15            for item in cart:
16                OrderItem.objects.create(
17                    order=order,
18                    product=item['product'],
19                    price=item['price'],
20                    quantity=item['quantity']
21                )
22            
23            # Clear cart and redirect to payment
24            cart.clear()
25            return redirect(reverse('payment:process'))

1# Secure payment processing
2def payment_process(request):
3    order_id = request.session.get('order_id')
4    order = get_object_or_404(Order, id=order_id)
5    
6    if request.method == 'POST':
7        nonce = request.POST.get('payment_method_nonce')
8        
9        # Create transaction with Braintree
10        result = gateway.transaction.sale({
11            'amount': str(order.get_total_cost()),
12            'payment_method_nonce': nonce,
13            'options': {
14                'submit_for_settlement': True
15            }
16        })
17        
18        if result.is_success:
19            # Payment successful
20            order.paid = True
21            order.braintree_id = result.transaction.id
22            order.save()
23            
24            # Send confirmation email
25            send_order_confirmation.delay(order.id)
26            
27            return redirect('payment:done')

1# Redis-powered recommendations
2class Recommender:
3    def get_product_key(self, id):
4        return f'product:{id}:purchased_with'
5    
6    def products_bought_together(self, products):
7        product_ids = [p.id for p in products]
8        for product_id in product_ids:
9            for with_id in product_ids:
10                if product_id != with_id:
11                    # Store purchase relationship
12                    r.zincrby(
13                        self.get_product_key(product_id),
14                        1,
15                        with_id
16                    )
17    
18    def suggest_products_for(self, products, max_results=6):
19        # Get product suggestions based on purchase history
20        if len(products) == 1:
21            suggestions = r.zrange(
22                self.get_product_key(products[0].id),
23                0, -1, desc=True
24            )[:max_results]
25        # Return actual Product objects
26        return Product.objects.filter(id__in=suggestions)

1<!-- Beautiful order confirmation email -->
2<div style="background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); 
3            padding: 40px 0; font-family: 'Segoe UI', sans-serif;">
4    <div style="max-width: 600px; margin: 0 auto; background: white; 
5                border-radius: 15px; overflow: hidden; box-shadow: 0 20px 40px rgba(0,0,0,0.1);">
6        
7        <div style="background: linear-gradient(135deg, #4CAF50, #45a049); 
8                    padding: 30px; text-align: center; color: white;">
9            <h1 style="margin: 0; font-size: 28px;">🎉 Order Confirmed!</h1>
10            <p style="margin: 10px 0 0; opacity: 0.9;">Thank you for shopping with MyShop</p>
11        </div>
12        
13        <div style="padding: 30px;">
14            <h2 style="color: #333; margin-bottom: 20px;">Order #{{ order.id }}</h2>
15            <!-- Order details with beautiful styling -->
16        </div>
17    </div>
18</div>

1# Multi-language URL patterns
2urlpatterns = [
3    path('i18n/', include('django.conf.urls.i18n')),
4]
5
6urlpatterns += i18n_patterns(
7    path('admin/', admin.site.urls),
8    path('cart/', include('cart.urls', namespace='cart')),
9    path('orders/', include('orders.urls', namespace='orders')),
10    path('', include('shop.urls', namespace='shop')),
11)

1<!-- Template with translation support -->
2<h1>{% trans "Welcome to MyShop" %}</h1>
3<p>{% trans "Discover amazing products at great prices!" %}</p>
4
5<!-- Language switcher -->
6<form action="{% url 'set_language' %}" method="post">
7    {% csrf_token %}
8    <select name="language" onchange="this.form.submit()">
9        {% get_current_language as LANGUAGE_CODE %}
10        {% get_available_languages as LANGUAGES %}
11        {% for lang_code, lang_name in LANGUAGES %}
12            <option value="{{ lang_code }}"{% if lang_code == LANGUAGE_CODE %} selected{% endif %}>
13                {{ lang_name }}
14            </option>
15        {% endfor %}
16    </select>
17</form>

1# Asynchronous email sending
2from celery import shared_task
3from django.core.mail import send_mail
4
5@shared_task
6def send_order_confirmation(order_id):
7    order = Order.objects.get(id=order_id)
8    
9    subject = f'MyShop - Order #{order.id} Confirmation'
10    message = f'Dear {order.first_name},\n\nYour order has been confirmed...'
11    
12    send_mail(
13        subject,
14        message,
15        'noreply@myshop.com',
16        [order.email],
17        html_message=get_order_email_html(order)
18    )

1# Smart caching for frequently accessed data
2from django.core.cache import cache
3
4def get_popular_products():
5    popular = cache.get('popular_products')
6    if popular is None:
7        popular = Product.objects.filter(available=True)\
8                                .order_by('-created')[:8]
9        cache.set('popular_products', popular, 60*15)  # Cache for 15 minutes
10    return popular

1# Custom admin views for business insights
2class OrderAdmin(admin.ModelAdmin):
3    list_display = ['id', 'first_name', 'last_name', 'email', 
4                   'address', 'postal_code', 'city', 'paid', 
5                   'created', 'updated']
6    list_filter = ['paid', 'created', 'updated']
7    
8    def get_queryset(self, request):
9        qs = super().get_queryset(request)
10        return qs.select_related('coupon')
11    
12    # Custom CSV export
13    actions = ['export_to_csv']
14    
15    def export_to_csv(self, request, queryset):
16        # Generate CSV for accounting software
17        pass

1# Coupon system for marketing campaigns
2class Coupon(models.Model):
3    code = models.CharField(max_length=50, unique=True)
4    valid_from = models.DateTimeField()
5    valid_to = models.DateTimeField()
6    discount = models.IntegerField(
7        validators=[MinValueValidator(0), MaxValueValidator(100)]
8    )
9    active = models.BooleanField()
10    
11    def __str__(self):
12        return self.code

1# Production database settings
2DATABASES = {
3    'default': {
4        'ENGINE': 'django.db.backends.postgresql',
5        'NAME': os.getenv('DB_NAME'),
6        'USER': os.getenv('DB_USER'),
7        'PASSWORD': os.getenv('DB_PASSWORD'),
8        'HOST': os.getenv('DB_HOST', 'localhost'),
9        'PORT': os.getenv('DB_PORT', '5432'),
10    }
11}

# Celery configuration
CELERY_BROKER_URL = 'redis://localhost:6379'
CELERY_RESULT_BACKEND = 'redis://localhost:6379'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'

1# Security settings that matter
2SECURE_BROWSER_XSS_FILTER = True
3SECURE_CONTENT_TYPE_NOSNIFF = True
4SECURE_HSTS_SECONDS = 31536000
5SECURE_HSTS_INCLUDE_SUBDOMAINS = True
6SECURE_HSTS_PRELOAD = True
7
8# CSRF protection
9CSRF_COOKIE_SECURE = True
10SESSION_COOKIE_SECURE = True
11
12# SQL injection prevention (Django ORM handles this)
13products = Product.objects.filter(name__icontains=search_term)  # Safe
14# Never: Product.objects.raw(f"SELECT * FROM products WHERE name LIKE '%{search_term}%'")  # Dangerous