不显示用 Django 模板编写的单选按钮

如何解决不显示用 Django 模板编写的单选按钮

我正在从文档中学习 Django。我在第 4 部分。有这样的代码 (detail.html)：

<form action="{% url 'polls:Vote' question.id %}" method="post">
{% csrf_token %}
<fieldset>
    <legend><h1>{{ question.question_text }}</h1></legend>
    {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}
    {% 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 %}
</fieldset>
<input type="submit" value="Vote">
</form>

这是views.py：

from django.http import HttpResponse,HttpResponseRedirect
from django.template import loader
from django.shortcuts import render,get_object_or_404
from django.http import Http404
from django.urls import reverse

from .models import Question,Choice


def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    context = {'latest_question_list': latest_question_list}
    return render(request,'polls/index.html',context)


def detail(request,question_id):
    question = get_object_or_404(Question,pk=question_id)
    return render(request,'polls/detail.html',{'question': question})

def results(request,'polls/results.html',{'question': question})


def Vote(request,pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError,Choice.DoesNotExist):
        return render(request,{
            'question': question,'error_message': "You didn't select a choice.",})
    else:
        selected_choice.Votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results',args=(question.id,)))

除单选按钮外的所有内容都显示出来。如何解决？ Python 3.6.3 Django 3.2.4