Django陷入困境的麻烦：NoReverseMatch at /

Question

I'm trying to access a page using a slugified url in my django blog app project.

This is what the problem template code looks like:

          {% for post in latest_post_list %}
    <li><a href="{% url 'blog:view_post' post.title_text|slugify %}">{{post.title_text}}</a>&nbsp;{{post.pub_date}}</li>

This is what my url route looks like:

 url(r'^(?P<post_name>)/$', views.view_post, name='view_post'))

and this is what my view function looks like:

def view_post(request, post_name):
pdb.set_trace()
try:
    post_name =  post_name.encode('ascii','ignore') #un-unicode name

    unslugified_post_name = post_name.replace('-', ' ')  #will get slugified name, replace all hyphens with spaces
    post = Post.objects.get(title_text=unslugified_post_name)


except Post.DoesNotExist:
    raise Http404("Post does not exist")

return render(request, 'blog/posts.djhtml', {'post': post})

And this is the stack trace for the error that I receive:

    Environment:


Request Method: GET
Request URL: http://127.0.0.1:8000/

Django Version: 1.7.3
Python Version: 2.7.3
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'blog')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Template error:
In template /home/andrew/projects/heroku-blog/My-Django-Blog/blog/templates/blog/index.djhtml, error at line 53
   Reverse for 'view_post' with arguments '(u'lorem-ipsum',)' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'blog/(?P<title_text>)/$']
   43 :     <h5><a href="/blog/">Programmer Plebeian</a></h5>


   44 :       </div>


   45 :       {{navbar|safe}}


   46 :       </div>


   47 :     </div>


   48 :     <div class="row">


   49 :       <div id="postindex" class="eleven columns">


   50 :           <ul>


   51 :         {% if latest_post_list %}


   52 :           {% for post in latest_post_list %}


   53 :         <li><a href=" {% url 'blog:view_post' post.title_text|slugify %} ">{{post.title_text}}</a>&nbsp;{{post.pub_date}}</li>


   54 :           {% endfor %}


   55 :       </ul>


   56 :         {% else %}


   57 :       <p>There is no blog post available here</p>


   58 :         {% endif %}


   59 :     </section>


   60 :       </div>


   61 :     </div>


   62 :   </div>


   63 : 


Traceback:
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/blog/views.py" in index
  13.     return render(request, 'blog/index.djhtml', context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/shortcuts.py" in render
  50.     return HttpResponse(loader.render_to_string(*args, **kwargs),
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/loader.py" in render_to_string
  178.         return t.render(context_instance)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/base.py" in render
  148.             return self._render(context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/base.py" in _render
  142.         return self.nodelist.render(context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/base.py" in render
  844.                 bit = self.render_node(node, context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  80.             return node.render(context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/defaulttags.py" in render
  312.                 return nodelist.render(context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/base.py" in render
  844.                 bit = self.render_node(node, context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  80.             return node.render(context)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/defaulttags.py" in render
  201.                             nodelist.append(node.render(context))
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/defaulttags.py" in render
  458.                         six.reraise(*exc_info)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/template/defaulttags.py" in render
  444.             url = reverse(view_name, args=args, kwargs=kwargs, current_app=context.current_app)
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py" in reverse
  551.     return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))
File "/home/andrew/projects/heroku-blog/My-Django-Blog/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py" in _reverse_with_prefix
  468.                              (lookup_view_s, args, kwargs, len(patterns), patterns))

Exception Type: NoReverseMatch at /
Exception Value: Reverse for 'view_post' with arguments '(u'lorem-ipsum',)' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'blog/(?P<title_text>)/$']

The value of the field that's causing this error is "lorem ipsum"

I know the problem is probably in the route regular expression, but I'm having trouble figuring out the proper regular expression for it, I'm new to them. All I'm trying to do right now is get the string that's passed to it, regardless of what it looks like. But if you're willing to show me a more robust one, I would be very appreciative.

Also, is there a way to prevent slugify from returning a unicode string?

Answer 1

Your regex for view_post is empty. Change it to this:

url(r'^(?P<post_name>[\w-]+)/$', views.view_post, name='view_post')