为啥我在 Django 中有这个错误？

Posted 2023-02-24

【中文标题】为啥我在 Django 中有这个错误？

【英文标题】：Why do I have this error in Django?为什么我在 Django 中有这个错误？

【发布时间】：2018-11-20 08:32:06

【问题描述】：

我正在关注 Django 教程过程，目前位于第 6 部分。

从我的网页单击列表时出现错误。我查找了问题发生的位置，但找不到。

这是来自网络浏览器的消息：

Page not found (404)
Request Method: GET
Request URL:    http://localhost:8000/polls/1//
Using the URLconf defined in mysite.urls, Django tried these URL patterns, in this order:

polls/ [name='index']
polls/ <int:pk>/ [name='detail']
polls/ <int:pk>/results/ [name='results']
polls/ <int:question_id>/vote/ [name='vote']
admin/
The current path, polls/1//, didn't match any of these.

You're seeing this error because you have DEBUG = True in your Django settings file. Change that to False, and Django will display a standard 404 page.

追溯 "GET /polls/1// HTTP/1.1" 404 2703

mysite/polls/views.py

from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.views import generic
from django.utils import timezone

from .models import Choice, Question

# ...
class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """
        Return the last five published questions (not including those set to be
        published in the future).
        """
        return Question.objects.filter(
            pub_date__lte=timezone.now()
        ).order_by('-pub_date')[:5]

class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'
    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        """
        return Question.objects.filter(pub_date__lte=timezone.now())

class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'

def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the question voting form.
        return render(request, 'polls/detail.html', 
            'question': question,
            'error_message': "You didn't select a choice.",
        )
    else:
        selected_choice.votes += 1
        selected_choice.save()
        # Always return an HttpResponseRedirect after successfully dealing
        # with POST data. This prevents data from being posted twice if a
        # user hits the Back button.
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))

mysite/polls/urls.py

from django.urls import path

from . import views

app_name = 'polls'
urlpatterns = [
    path('', views.IndexView.as_view(), name='index'),
    path('<int:pk>/', views.DetailView.as_view(), name='detail'),
    path('<int:pk>/results/', views.ResultsView.as_view(), name='results'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
]

mysite/urls.py

from django.contrib import admin
from django.urls import include, path

urlpatterns = [
    path('polls/', include('polls.urls')),
    path('admin/', admin.site.urls),
]

mysite/polls/templates/polls/index.html

% load static %

<link rel="stylesheet" type="text/css" href="% static 'polls/style.css' %" />

% if latest_question_list %
    <ul>
    % for question in latest_question_list %
        <li><a href="% url 'polls:detail' question.id %/"> question.question_text </a></li>
    % endfor %
    </ul>
% else %
    <p>No polls are available.</p>
% endif %

mysite/polls/templates/polls/detail.html

<h1> question.question_text </h1>

% if error_message %<p><strong> error_message </strong></p>% endif %

<form action="% url 'polls:vote' question.id %" method="post">
% csrf_token %
% for choice in question.choice_set.all %
    <input type="radio" name="choice" id="choice forloop.counter " value=" choice.id " />
    <label for="choice forloop.counter "> choice.choice_text </label><br />
% endfor %
<input type="submit" value="Vote" />
</form>

mysite/polls/templates/polls/result.html

<h1> question.question_text </h1>

<ul>
% for choice in question.choice_set.all %
    <li> choice.choice_text  --  choice.votes  vote choice.votes|pluralize </li>
% endfor %
</ul>

<a href="% url 'polls:detail' question.id %">Vote again?</a>

【参考方案1】：

您的网址末尾有两个斜杠（'//'），这应该只有一个：

http://localhost:8000/polls/1/

更具体地说，在您的 polls/index.html 模板中，您有以下行：

<li><a href="% url 'polls:detail' question.id %/"> question.question_text </a></li>

在该行中，这部分会为您生成 url：

% url 'polls:detail' question.id %

变成：

http://localhost:8000/polls/1/

但是你在它后面添加了一个额外的斜线，请看下面字符串的末尾：

"% url 'polls:detail' question.id %/"

删除它，我认为您的代码应该可以工作。