我有一个具有以下模型的 Django 应用程序：
class Topic(models.Model):
title = models.CharField(max_length=140)
有一个 URL，应该显示Topic的详细信息：
urlpatterns = patterns('',
[...]
(r'^topic/(\d+)$', 'history_site.views.topic_details'),
[...]
)
history_site.views.topic_details定义为
from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import render_to_response
from django.template.loader import get_template
from django.template import Context, RequestContext
from django.views.decorators.csrf import csrf_protect
import logging
from opinions.models import Topic
from django.template.response import TemplateResponse
logging.basicConfig(filename='history-site.log',level=logging.DEBUG)
def topic_details(request, topic_id_string):
topic_id = int(topic_id_string)
topic = Topic.objects.get(id=topic_id)
return TemplateResponse('topic.tpl.html', locals())
topic.tpl.html有以下内容：
<!DOCTYPE html>
{% block prehtml %}
{% endblock %}
<html>
<head>
<title>{% block title %}{% endblock %}</title>
{% block scripts %}{% endblock %}
</head>
<body>
<h1>{{ topic.title }} </h1>
{% block content %}
{% endblock %}
</body>
</html>
当我尝试访问 URLhttp://127.0.0.1:8000/topic/1时出现错误'str' object has no attribute 'META'。
为什么？
我该如何解决？