小白学Python - 使用 Django 的电子商务网站

该项目涉及开发虚拟网站“电子商务网站”。它为用户提供了商店中可供购买的各种产品的列表。为了方便用户网上购物，为用户提供了购物车。选择商品后，将发送至订单确认流程。该系统使用Python 的Web框架`Django`实现。开发一个电子商务网站，需要学习和了解很多技术。

范围：项目范围将仅限于电子商务网站的某些功能。它将显示产品，客户可以选择目录和选择产品，并且可以从购物车中删除产品，并指定每件商品的数量。选定的商品将被收集到购物车中。结帐时，卡上的商品将作为订单显示。客户可以为购物车中的商品付款以完成订单。该项目未来前景广阔。该项目还通过使用登录 ID 和密码来提供安全性，以便未经授权的用户无法访问您的帐户。唯一具有适当访问权限的授权人员可以访问该软件。

项目中使用的技术： 

Django 框架和 Django 默认自带的 SQLite 数据库。

构建项目所需的技能： 

了解 Python 和 Django 框架基础知识。

ER 和用例图

客户界面：

1. 顾客购买产品
2. 客户更改数量
3. 客户将商品添加到购物车
4. 客户查看购物车
5. 顾客结账
6. 客户发送订单

客户 ER 图

客户用例图

管理界面：

1. 管理员登录
2. 管理员插入项目
3. 管理员删除项目
4. 管理员修改项目

管理员 ER 图

管理员用例图

分步实施： 

• 创建普通项目：打开 IDE 并通过选择“文件”->“新建项目”创建普通项目。
• 安装 Django：接下来，我们将从终端安装 Django 模块。我们将使用 PyCharm 集成终端来完成此任务。还可以在 Windows 上使用 cmd 通过运行python -m pip install django命令来安装模块
• 检查已安装的 Django 版本：要检查已安装的 Django 版本，可以运行python -m django -version命令，如下所示。
• 创建 Django 项目：当我们执行django-admin startproject命令时，它将在我们已经创建的普通项目中创建一个 Django 项目。django-admin startproject 项目名称。
• 检查Python3版本：python3 –version
• 运行默认的 Django Web 服务器：- Django 内部提供了一个默认的 Web 服务器，我们可以在其中启动我们的应用程序。终端中的python manage.py runserver命令。默认情况下，服务器在端口 8000 上运行。通过突出显示的 URL 访问 Web 服务器。

使用文本编辑器打开项目文件夹。目录结构应如下所示：

项目结构

现在在电子商务网站的settings.py中添加商店应用程序。

urls.py

该文件包含网站使用的所有 URL 模式

from django.contrib import admin 
from django.urls import path, include 
from django.conf.urls.static import static 
from . import settings 

urlpatterns = [ 
	path('admin/', admin.site.urls), 
	path('', include('store.urls')) 
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

模型

下面的屏幕截图显示了我们需要创建的所需模型。这些模型是将存储在 SQLite 数据库中的表。

让我们看看每个模型以及每个模型所需的字段。

category.py

from django.db import models 

class Category(models.Model): 
	name = models.CharField(max_length=50) 

	@staticmethod
	def get_all_categories(): 
		return Category.objects.all() 

	def __str__(self): 
		return self.name

customer.py

from django.db import models 


class Customer(models.Model): 
	first_name = models.CharField(max_length=50) 
	last_name = models.CharField(max_length=50) 
	phone = models.CharField(max_length=10) 
	email = models.EmailField() 
	password = models.CharField(max_length=100) 

	# to save the data 
	def register(self): 
		self.save() 

	@staticmethod
	def get_customer_by_email(email): 
		try: 
			return Customer.objects.get(email=email) 
		except: 
			return False

	def isExists(self): 
		if Customer.objects.filter(email=self.email): 
			return True

		return False

products.py

from django.db import models 
from .category import Category 


class Products(models.Model): 
	name = models.CharField(max_length=60) 
	price = models.IntegerField(default=0) 
	category = models.ForeignKey(Category, on_delete=models.CASCADE, default=1) 
	description = models.CharField( 
		max_length=250, default='', blank=True, null=True) 
	image = models.ImageField(upload_to='uploads/products/') 

	@staticmethod
	def get_products_by_id(ids): 
		return Products.objects.filter(id__in=ids) 

	@staticmethod
	def get_all_products(): 
		return Products.objects.all() 

	@staticmethod
	def get_all_products_by_categoryid(category_id): 
		if category_id: 
			return Products.objects.filter(category=category_id) 
		else: 
			return Products.get_all_products()

Orders.py

from django.db import models 
from .product import Products 
from .customer import Customer 
import datetime 


class Order(models.Model): 
	product = models.ForeignKey(Products, 
								on_delete=models.CASCADE) 
	customer = models.ForeignKey(Customer, 
								on_delete=models.CASCADE) 
	quantity = models.IntegerField(default=1) 
	price = models.IntegerField() 
	address = models.CharField(max_length=50, default='', blank=True) 
	phone = models.CharField(max_length=50, default='', blank=True) 
	date = models.DateField(default=datetime.datetime.today) 
	status = models.BooleanField(default=False) 

	def placeOrder(self): 
		self.save() 

	@staticmethod
	def get_orders_by_customer(customer_id): 
		return Order.objects.filter(customer=customer_id).order_by('-date')

视图

在视图中，我们创建一个名为home.py、login.py、signup.py、cart.py、checkout.py、orders.py 的视图  ，它接受请求并呈现 HTML 作为响应。在模板中创建home.html、login.html、signup.html、cart.html、checkout.html、orders.html 。并将视图映射到 store\urls.py 文件夹。 

from django.contrib import admin 
from django.urls import path 
from .views.home import Index, store 
from .views.signup import Signup 
from .views.login import Login, logout 
from .views.cart import Cart 
from .views.checkout import CheckOut 
from .views.orders import OrderView 
from .middlewares.auth import auth_middleware 


urlpatterns = [ 
	path('', Index.as_view(), name='homepage'), 
	path('store', store, name='store'), 

	path('signup', Signup.as_view(), name='signup'), 
	path('login', Login.as_view(), name='login'), 
	path('logout', logout, name='logout'), 
	path('cart', auth_middleware(Cart.as_view()), name='cart'), 
	path('check-out', CheckOut.as_view(), name='checkout'), 
	path('orders', auth_middleware(OrderView.as_view()), name='orders'), 

]

main.py

from django.shortcuts import render, redirect, HttpResponseRedirect 
from store.models.product import Products 
from store.models.category import Category 
from django.views import View 


# Create your views here. 
class Index(View): 

	def post(self, request): 
		product = request.POST.get('product') 
		remove = request.POST.get('remove') 
		cart = request.session.get('cart') 
		if cart: 
			quantity = cart.get(product) 
			if quantity: 
				if remove: 
					if quantity <= 1: 
						cart.pop(product) 
					else: 
						cart[product] = quantity-1
				else: 
					cart[product] = quantity+1

			else: 
				cart[product] = 1
		else: 
			cart = {} 
			cart[product] = 1

		request.session['cart'] = cart 
		print('cart', request.session['cart']) 
		return redirect('homepage') 

	def get(self, request): 
		# print() 
		return HttpResponseRedirect(f'/store{request.get_full_path()[1:]}') 


def store(request): 
	cart = request.session.get('cart') 
	if not cart: 
		request.session['cart'] = {} 
	products = None
	categories = Category.get_all_categories() 
	categoryID = request.GET.get('category') 
	if categoryID: 
		products = Products.get_all_products_by_categoryid(categoryID) 
	else: 
		products = Products.get_all_products() 

	data = {} 
	data['products'] = products 
	data['categories'] = categories 

	print('you are : ', request.session.get('email')) 
	return render(request, 'index.html', data)

login.py

from django.shortcuts import render, redirect, HttpResponseRedirect 
from django.contrib.auth.hashers import check_password 
from store.models.customer import Customer 
from django.views import View 


class Login(View): 
	return_url = None

	def get(self, request): 
		Login.return_url = request.GET.get('return_url') 
		return render(request, 'login.html') 

	def post(self, request): 
		email = request.POST.get('email') 
		password = request.POST.get('password') 
		customer = Customer.get_customer_by_email(email) 
		error_message = None
		if customer: 
			flag = check_password(password, customer.password) 
			if flag: 
				request.session['customer'] = customer.id

				if Login.return_url: 
					return HttpResponseRedirect(Login.return_url) 
				else: 
					Login.return_url = None
					return redirect('homepage') 
			else: 
				error_message = 'Invalid !!'
		else: 
			error_message = 'Invalid !!'

		print(email, password) 
		return render(request, 'login.html', {'error': error_message}) 


def logout(request): 
	request.session.clear() 
	return redirect('login')

register.py

from django.shortcuts import render, redirect 
from django.contrib.auth.hashers import make_password 
from store.models.customer import Customer 
from django.views import View 


class Signup (View): 
	def get(self, request): 
		return render(request, 'signup.html') 

	def post(self, request): 
		postData = request.POST 
		first_name = postData.get('firstname') 
		last_name = postData.get('lastname') 
		phone = postData.get('phone') 
		email = postData.get('email') 
		password = postData.get('password') 
		# validation 
		value = { 
			'first_name': first_name, 
			'last_name': last_name, 
			'phone': phone, 
			'email': email 
		} 
		error_message = None

		customer = Customer(first_name=first_name, 
							last_name=last_name, 
							phone=phone, 
							email=email, 
							password=password) 
		error_message = self.validateCustomer(customer) 

		if not error_message: 
			print(first_name, last_name, phone, email, password) 
			customer.password = make_password(customer.password) 
			customer.register() 
			return redirect('homepage') 
		else: 
			data = { 
				'error': error_message, 
				'values': value 
			} 
			return render(request, 'signup.html', data) 

	def validateCustomer(self, customer): 
		error_message = None
		if (not customer.first_name): 
			error_message = "Please Enter your First Name !!"
		elif len(customer.first_name) < 3: 
			error_message = 'First Name must be 3 char long or more'
		elif not customer.last_name: 
			error_message = 'Please Enter your Last Name'
		elif len(customer.last_name) < 3: 
			error_message = 'Last Name must be 3 char long or more'
		elif not customer.phone: 
			error_message = 'Enter your Phone Number'
		elif len(customer.phone) < 10: 
			error_message = 'Phone Number must be 10 char Long'
		elif len(customer.password) < 5: 
			error_message = 'Password must be 5 char long'
		elif len(customer.email) < 5: 
			error_message = 'Email must be 5 char long'
		elif customer.isExists(): 
			error_message = 'Email Address Already Registered..'
		# saving 

		return error_message

cart.py

from django.db import models 
from .product import Products 
from .customer import Customer 
import datetime 


class Order(models.Model): 
	product = models.ForeignKey(Products, 
								on_delete=models.CASCADE) 
	customer = models.ForeignKey(Customer, 
								on_delete=models.CASCADE) 
	quantity = models.IntegerField(default=1) 
	price = models.IntegerField() 
	address = models.CharField(max_length=50, default='', blank=True) 
	phone = models.CharField(max_length=50, default='', blank=True) 
	date = models.DateField(default=datetime.datetime.today) 
	status = models.BooleanField(default=False) 

	def placeOrder(self): 
		self.save() 

	@staticmethod
	def get_orders_by_customer(customer_id): 
		return Order.objects.filter(customer=customer_id).order_by('-date')

checkout.py

from django.shortcuts import render, redirect 

from django.contrib.auth.hashers import check_password 
from store.models.customer import Customer 
from django.views import View 

from store.models.product import Products 
from store.models.orders import Order 


class CheckOut(View): 
	def post(self, request): 
		address = request.POST.get('address') 
		phone = request.POST.get('phone') 
		customer = request.session.get('customer') 
		cart = request.session.get('cart') 
		products = Products.get_products_by_id(list(cart.keys())) 
		print(address, phone, customer, cart, products) 

		for product in products: 
			print(cart.get(str(product.id))) 
			order = Order(customer=Customer(id=customer), 
						product=product, 
						price=product.price, 
						address=address, 
						phone=phone, 
						quantity=cart.get(str(product.id))) 
			order.save() 
		request.session['cart'] = {} 

		return redirect('cart')

orders.py

from django.shortcuts import render, redirect 
from django.contrib.auth.hashers import check_password 
from store.models.customer import Customer 
from django.views import View 
from store.models.product import Products 
from store.models.orders import Order 
from store.middlewares.auth import auth_middleware 


class OrderView(View): 

	def get(self, request): 
		customer = request.session.get('customer') 
		orders = Order.get_orders_by_customer(customer) 
		print(orders) 
		return render(request, 'orders.html', {'orders': orders})

Output 

该项目已经包含了很多功能。主要受益者是需要更长时间进行在线操作的客户和管理员。此外，未来还可以识别并合并其他功能。需要更多的时间和精力来了解需求并将其调整为计算机化系统以适应附加功能。