Django框架的重要性
Django是一个功能强大的Python Web框架，采用”电池包含”的设计哲学，提供了完整的Web开发解决方案。掌握Django对于构建复杂的企业级Web应用至关重要，它提供了ORM、模板系统、管理后台、安全性等丰富的功能。
项目创建和结构
1. 项目初始化
# 创建Django项目
django-admin startproject myproject
cd myproject
# 创建应用
python manage.py startapp myapp
# 数据库迁移
python manage.py makemigrations
python manage.py migrate
# 创建超级用户
python manage.py createsuperuser
# 启动开发服务器
python manage.py runserver
2. 项目结构说明
def django_structure_demo():
"""Django项目结构演示"""
print("=== Django项目结构 ===")
print("myproject/")
print("├── manage.py # Django管理脚本")
print("├── myproject/")
print("│ ├── __init__.py")
print("│ ├── settings.py # 项目配置")
print("│ ├── urls.py # URL路由配置")
print("│ ├── wsgi.py # WSGI配置")
print("│ └── asgi.py # ASGI配置")
print("└── myapp/")
print(" ├── __init__.py")
print(" ├── admin.py # 管理后台配置")
print(" ├── apps.py # 应用配置")
print(" ├── models.py # 数据模型")
print(" ├── views.py # 视图函数")
print(" ├── urls.py # URL配置")
print(" ├── tests.py # 测试文件")
print(" └── migrations/ # 数据库迁移文件")
django_structure_demo()
模型（Models）设计
1. 基础模型定义
from django.db import models
from django.contrib.auth.models import User
from django.urls import reverse
class Category(models.Model):
"""文章分类模型"""
name = models.CharField(max_length=100, verbose_name="分类名称")
description = models.TextField(blank=True, verbose_name="分类描述")
created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
class Meta:
verbose_name = "分类"
verbose_name_plural = "分类"
ordering = ['name']
def __str__(self):
return self.name
class Tag(models.Model):
"""标签模型"""
name = models.CharField(max_length=50, unique=True, verbose_name="标签名称")
color = models.CharField(max_length=7, default="#007bff", verbose_name="标签颜色")
def __str__(self):
return self.name
class Article(models.Model):
"""文章模型"""
STATUS_CHOICES = [
('draft', '草稿'),
('published', '已发布'),
('archived', '已归档'),
]
title = models.CharField(max_length=200, verbose_name="标题")
slug = models.SlugField(max_length=200, unique=True, verbose_name="URL别名")
content = models.TextField(verbose_name="内容")
excerpt = models.TextField(max_length=500, blank=True, verbose_name="摘要")
author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name="作者")
category = models.ForeignKey(Category, on_delete=models.SET_NULL, null=True, verbose_name="分类")
tags = models.ManyToManyField(Tag, blank=True, verbose_name="标签")
status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='draft', verbose_name="状态")
created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
updated_at = models.DateTimeField(auto_now=True, verbose_name="更新时间")
published_at = models.DateTimeField(null=True, blank=True, verbose_name="发布时间")
view_count = models.PositiveIntegerField(default=0, verbose_name="浏览次数")
class Meta:
verbose_name = "文章"
verbose_name_plural = "文章"
ordering = ['-created_at']
def __str__(self):
return self.title
def get_absolute_url(self):
"""获取文章详情页URL"""
return reverse('article_detail', kwargs={'slug': self.slug})
def save(self, *args, **kwargs):
"""保存时自动设置发布时间"""
if self.status == 'published' and not self.published_at:
from django.utils import timezone
self.published_at = timezone.now()
super().save(*args, **kwargs)
2. 模型关系和方法
class Comment(models.Model):
"""评论模型"""
article = models.ForeignKey(Article, on_delete=models.CASCADE, related_name='comments', verbose_name="文章")
author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name="评论者")
content = models.TextField(verbose_name="评论内容")
parent = models.ForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, verbose_name="父评论")
created_at = models.DateTimeField(auto_now_add=True, verbose_name="评论时间")
is_approved = models.BooleanField(default=False, verbose_name="是否审核通过")
class Meta:
verbose_name = "评论"
verbose_name_plural = "评论"
ordering = ['created_at']
def __str__(self):
return f"{self.author.username} 对 {self.article.title} 的评论"
def get_replies(self):
"""获取回复"""
return Comment.objects.filter(parent=self)
def model_demo():
"""模型演示"""
print("=== Django模型设计演示 ===")
print("模型特性:")
print("- 自动数据库表生成")
print("- 字段类型丰富")
print("- 关系映射")
print("- 元数据配置")
print("- 自定义方法")
print("- 信号机制")
model_demo()
视图（Views）设计
1. 函数式视图
from django.shortcuts import render, get_object_or_404, redirect
from django.http import JsonResponse, HttpResponse
from django.core.paginator import Paginator
from django.db.models import Q
from .models import Article, Category, Tag, Comment
from .forms import ArticleForm, CommentForm
def article_list(request):
"""文章列表视图"""
# 获取查询参数
search = request.GET.get('search', '')
category_id = request.GET.get('category', '')
# 构建查询
articles = Article.objects.filter(status='published')
if search:
articles = articles.filter(
Q(title__icontains=search) |
Q(content__icontains=search)
)
if category_id:
articles = articles.filter(category_id=category_id)
# 分页
paginator = Paginator(articles, 10) # 每页10篇文章
page_number = request.GET.get('page')
page_obj = paginator.get_page(page_number)
# 获取分类和标签用于筛选
categories = Category.objects.all()
tags = Tag.objects.all()
context = {
'page_obj': page_obj,
'articles': page_obj.object_list,
'categories': categories,
'tags': tags,
'search': search,
'selected_category': category_id,
}
return render(request, 'articles/list.html', context)
2. 类视图
from django.views.generic import ListView, DetailView, CreateView
from django.contrib.auth.mixins import LoginRequiredMixin
from django.urls import reverse_lazy
from django.contrib import messages
class ArticleListView(ListView):
"""文章列表类视图"""
model = Article
template_name = 'articles/list.html'
context_object_name = 'articles'
paginate_by = 10
def get_queryset(self):
"""获取查询集"""
queryset = Article.objects.filter(status='published')
# 搜索
search = self.request.GET.get('search')
if search:
queryset = queryset.filter(
Q(title__icontains=search) |
Q(content__icontains=search)
)
return queryset.select_related('author', 'category').prefetch_related('tags')
def get_context_data(self, **kwargs):
"""添加上下文数据"""
context = super().get_context_data(**kwargs)
context['categories'] = Category.objects.all()
context['tags'] = Tag.objects.all()
context['search'] = self.request.GET.get('search', '')
return context
class ArticleDetailView(DetailView):
"""文章详情类视图"""
model = Article
template_name = 'articles/detail.html'
context_object_name = 'article'
def get_queryset(self):
return Article.objects.filter(status='published')
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
article = context['article']
# 增加浏览次数
article.view_count += 1
article.save(update_fields=['view_count'])
# 相关文章
context['related_articles'] = Article.objects.filter(
category=article.category,
status='published'
).exclude(id=article.id)[:5]
return context
管理后台配置
1. 基础管理配置
from django.contrib import admin
from .models import Article, Category, Tag, Comment
@admin.register(Category)
class CategoryAdmin(admin.ModelAdmin):
"""分类管理"""
list_display = ['name', 'created_at']
search_fields = ['name']
list_filter = ['created_at']
@admin.register(Tag)
class TagAdmin(admin.ModelAdmin):
"""标签管理"""
list_display = ['name', 'color']
search_fields = ['name']
@admin.register(Article)
class ArticleAdmin(admin.ModelAdmin):
"""文章管理"""
list_display = ['title', 'author', 'category', 'status', 'created_at', 'view_count']
list_filter = ['status', 'category', 'created_at', 'author']
search_fields = ['title', 'content']
prepopulated_fields = {'slug': ('title',)}
filter_horizontal = ['tags']
date_hierarchy = 'created_at'
fieldsets = (
('基本信息', {
'fields': ('title', 'slug', 'author', 'category')
}),
('内容', {
'fields': ('content', 'excerpt', 'tags')
}),
('发布设置', {
'fields': ('status', 'published_at')
}),
('统计信息', {
'fields': ('view_count',),
'classes': ('collapse',)
}),
)
def get_queryset(self, request):
"""自定义查询集"""
return super().get_queryset(request).select_related('author', 'category')
@admin.register(Comment)
class CommentAdmin(admin.ModelAdmin):
"""评论管理"""
list_display = ['author', 'article', 'created_at', 'is_approved']
list_filter = ['is_approved', 'created_at']
search_fields = ['content', 'author__username']
actions = ['approve_comments', 'disapprove_comments']
def approve_comments(self, request, queryset):
"""批量审核评论"""
queryset.update(is_approved=True)
self.message_user(request, f'已审核 {queryset.count()} 条评论')
approve_comments.short_description = "审核选中的评论"
def disapprove_comments(self, request, queryset):
"""批量取消审核"""
queryset.update(is_approved=False)
self.message_user(request, f'已取消审核 {queryset.count()} 条评论')
disapprove_comments.short_description = "取消审核选中的评论"
总结
Django入门的关键要点：
- 项目结构：清晰的文件组织和模块化设计
- 模型设计：ORM映射、关系定义、字段类型
- 视图处理：函数视图和类视图的使用场景
- 模板系统：模板继承、标签、过滤器
- URL配置：路由管理和参数传递
- 管理后台：快速数据管理界面
- 表单处理：数据验证和用户交互
掌握这些Django基础概念，可以快速构建功能完整的Web应用，为深入学习Django高级特性打下坚实基础。
转载请注明：周志洋的博客 » Python Web开发-Django入门详解
