Python中的Django视图与路由

from django.urls import path
from . import views
# URL与视图的映射列表
urlpatterns = [
    # 首页：访问http://127.0.0.1:8000/myapp/ 触发views.home视图
    path('', views.home, name='home'),
    # 文章详情：访问http://127.0.0.1:8000/myapp/article/1/ 触发views.article_detail
    path('article/<int:pk>/', views.article_detail, name='article_detail'),
    # 分类列表：访问http://127.0.0.1:8000/myapp/category/tech/ 触发views.category_articles
    path('category/<slug:slug>/', views.category_articles, name='category_articles'),
]

# views.py
from django.shortcuts import render, get_object_or_404
from .models import Article
def article_detail(request, pk):
    # 根据pk（文章ID）查询文章，不存在则返回404
    article = get_object_or_404(Article, pk=pk)
    # 渲染模板并传递文章数据
    return render(request, 'article_detail.html', {'article': article})

# urls.py
from django.urls import re_path
from . import views
urlpatterns = [
    # 正则表达式：(?P<year>[0-9]{4}) 表示提取4位数字作为year参数
    re_path(r'^article/(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/$', views.article_archive, name='article_archive'),
]
# views.py
def article_archive(request, year, month):
    # 筛选指定年月的文章
    articles = Article.objects.filter(created_at__year=year, created_at__month=month)
    return render(request, 'article_archive.html', {'articles': articles, 'year': year, 'month': month})

from django.urls import reverse
def some_view(request):
    # 根据别名'article_detail'和参数pk=1生成URL：/myapp/article/1/
    article_url = reverse('article_detail', args=[1])
    # 重定向到该URL
    return redirect(article_url)

<!-- 模板中生成文章详情页链接 -->
<a href="{% url 'article_detail' article.pk %}" rel="external nofollow" >{{ article.title }}</a>

# blog/urls.py
app_name = 'blog'  # 定义应用级命名空间
urlpatterns = [
    path('', views.index, name='index'),  # 别名index
]

# project/urls.py
from django.urls import path, include
urlpatterns = [
    path('blog/', include('blog.urls', namespace='blog')),  # 关联命名空间
    path('shop/', include('shop.urls', namespace='shop')),
]

# views.py
from django.http import HttpResponse
def hello(request):
    # 返回文本响应
    return HttpResponse('Hello, Django!')

from django.http import HttpResponse, HttpResponseNotFound
# 返回404 Not Found
def page_not_found(request):
    return HttpResponseNotFound('页面不存在！')
# 返回204 No Content（成功但无内容）
def success_no_content(request):
    return HttpResponse(status=204)

from django.shortcuts import get_object_or_404
from .models import Article
def article_detail(request, pk):
    # 若Article不存在（pk不存在），自动抛出404
    article = get_object_or_404(Article, pk=pk)
    return render(request, 'article_detail.html', {'article': article})

# project/urls.py
from django.shortcuts import render
# 404页面处理器
def handler404(request, exception):
    return render(request, '404.html', status=404)
# 500页面处理器
def handler500(request):
    return render(request, '500.html', status=500)

import asyncio
from django.http import HttpResponse
# 异步视图：使用async def定义
async def async_view(request):
    # 模拟IO等待（如调用外部API）
    await asyncio.sleep(1)
    return HttpResponse('这是异步视图返回的内容！')

from django.shortcuts import render
def index(request):
    # 上下文数据：传递给模板的变量
    context = {'name': 'Django', 'version': '5.0'}
    # 渲染index.html模板，传递context
    return render(request, 'index.html', context)

from django.shortcuts import redirect
from django.urls import reverse
def redirect_to_home(request):
    # 重定向到别名'home'的URL
    return redirect('home')
def redirect_to_article(request, pk):
    # 重定向到带参数的URL
    return redirect('article_detail', pk=pk)
def redirect_to_external(request):
    # 重定向到外部链接
    return redirect('https://example.com')

from django.shortcuts import get_list_or_404
from .models import Article
def published_articles(request):
    # 筛选已发布的文章，无结果则返回404
    articles = get_list_or_404(Article, is_published=True)
    return render(request, 'article_list.html', {'articles': articles})

from django.views.decorators.http import require_http_methods, require_GET, require_POST
# 仅允许GET和POST请求
@require_http_methods(['GET', 'POST'])
def create_article(request):
    if request.method == 'GET':
        # 显示创建表单
        return render(request, 'article_form.html')
    elif request.method == 'POST':
        # 处理表单提交
        pass
# 仅允许GET请求
@require_GET
def article_list(request):
    pass
# 仅允许POST请求
@require_POST
def delete_article(request):
    pass

from django.contrib.auth.decorators import login_required
@login_required
def user_profile(request):
    # 仅登录用户可访问个人中心
    pass

from django.contrib.auth.decorators import permission_required
# 要求用户有"修改文章"的权限
@permission_required('myapp.change_article')
def edit_article(request, pk):
    pass

from django.views.decorators.gzip import gzip_page
@gzip_page
def large_page(request):
    # 压缩大页面的响应
    pass

# 获取URL中的查询参数：?name=Django
name = request.GET.get('name')

# 获取表单中的email字段
email = request.POST.get('email')

# 获取用户浏览器信息
user_agent = request.META.get('HTTP_USER_AGENT')
# 获取客户端IP
ip = request.META.get('REMOTE_ADDR')

from django.http import JsonResponse
def api_data(request):
    data = {
        'name': 'Django',
        'features': ['ORM', 'Admin', 'Templates']
    }
    return JsonResponse(data)  # 自动设置Content-Type: application/json

from django.http import FileResponse
import os
def download_pdf(request):
    file_path = '/path/to/document.pdf'
    # 打开文件并返回下载响应
    response = FileResponse(open(file_path, 'rb'))
    # 设置下载文件名
    response['Content-Disposition'] = 'attachment; filename="document.pdf"'
    return response

# forms.py
from django import forms
class UploadFileForm(forms.Form):
    title = forms.CharField(max_length=50)  # 文件标题
    file = forms.FileField()  # 文件上传字段

# views.py
from django.shortcuts import render
from .forms import UploadFileForm
import os
def upload_file(request):
    if request.method == 'POST':
        # 初始化表单并传递POST数据和文件
        form = UploadFileForm(request.POST, request.FILES)
        if form.is_valid():
            title = form.cleaned_data['title']
            uploaded_file = request.FILES['file']  # 获取上传的文件
            # 分块保存文件（适合大文件）
            upload_dir = 'uploads/'
            os.makedirs(upload_dir, exist_ok=True)  # 确保目录存在
            with open(os.path.join(upload_dir, uploaded_file.name), 'wb+') as f:
                for chunk in uploaded_file.chunks():
                    f.write(chunk)
            # 上传成功，跳转成功页
            return render(request, 'upload_success.html')
    else:
        # GET请求：显示空表单
        form = UploadFileForm()
    return render(request, 'upload.html', {'form': form})

<!-- upload.html -->
<form method="post" enctype="multipart/form-data">
    {% csrf_token %}  <!-- 必须添加，防止CSRF攻击 -->
    {{ form.as_p }}   <!-- 渲染表单字段 -->
    <button type="submit">上传</button>
</form>