Django 'polls' is not a registered namespace

Question

I'm learning Django from [THIS][1] tutorial. Everything worked perfectly until this step:

Now change your polls/index.html template from:

<li><a href="{% url 'detail' poll.id %}">{{ poll.question }}</a></li>

to point at the namespaced detail view:

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

You can see the whole paragraph [HERE][2].

And that's what happened after I changed 'detail' into 'polls:detail':

NoReverseMatch at /polls/
'polls' is not a registered namespace
Request Method: GET
Request URL:    http://127.0.0.1:8000/polls/
Django Version: 1.6.4
Exception Type: NoReverseMatch
Exception Value:    
'polls' is not a registered namespace
Exception Location: D:\Programy\Python 3.4\lib\site-packages\django\core\urlresolvers.py in reverse, line 528
Python Executable:  D:\Programy\Python 3.4\python.exe
Python Version: 3.4.0
Python Path:    
['D:\\dziango\\strona1',
 'D:\\Programy\\Python 3.4\\python34.zip',
 'D:\\Programy\\Python 3.4\\DLLs',
 'D:\\Programy\\Python 3.4\\lib',
 'D:\\Programy\\Python 3.4',
 'D:\\Programy\\Python 3.4\\lib\\site-packages']
Server time:    Wed, 21 May 2014 16:36:13 +0200

and here is my Traceback:

Environment:


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

Django Version: 1.6.4
Python Version: 3.4.0
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'polls')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Template error:
In template D:\dziango\strona1\polls\templates\polls\index.html, error at line 1
   'polls' is not a registered namespace
   1 : {% if latest_poll_list %}
    <ul>
    {% for poll in latest_poll_list %}
        <li><a href=" {% url 'polls:detail' poll.id %} ">{{ poll.question }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>Nie ma ankiet.</p>
{% endif %}

Traceback:
File "D:\Programy\Python 3.4\lib\site-packages\django\core\handlers\base.py" in get_response
  114.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "D:\dziango\strona1\polls\views.py" in index
  11.     return render(request, 'polls/index.html', context)
File "D:\Programy\Python 3.4\lib\site-packages\django\shortcuts\__init__.py" in render
  53.     return HttpResponse(loader.render_to_string(*args, **kwargs),
File "D:\Programy\Python 3.4\lib\site-packages\django\template\loader.py" in render_to_string
  169.         return t.render(context_instance)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\base.py" in render
  140.             return self._render(context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\base.py" in _render
  134.         return self.nodelist.render(context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\base.py" in render
  840.                 bit = self.render_node(node, context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\debug.py" in render_node
  78.             return node.render(context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\defaulttags.py" in render
  305.                 return nodelist.render(context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\base.py" in render
  840.                 bit = self.render_node(node, context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\debug.py" in render_node
  78.             return node.render(context)
File "D:\Programy\Python 3.4\lib\site-packages\django\template\defaulttags.py" in render
  196.                         nodelist.append(node.render(context))
File "D:\Programy\Python 3.4\lib\site-packages\django\template\defaulttags.py" in render
  447.                         six.reraise(*exc_info)
File "D:\Programy\Python 3.4\lib\site-packages\django\utils\six.py" in reraise
  550.         raise value
File "D:\Programy\Python 3.4\lib\site-packages\django\template\defaulttags.py" in render
  433.             url = reverse(view_name, args=args, kwargs=kwargs, current_app=context.current_app)
File "D:\Programy\Python 3.4\lib\site-packages\django\core\urlresolvers.py" in reverse
  528.                                          key)

Exception Type: NoReverseMatch at /polls/
Exception Value: 'polls' is not a registered namespace

I tried every single solution from [THIS][3] similar topic but none of them works for me. I don't paste my code here because I wrote it all from that tutorial and it's exactly the same. Everything I did was done step by step according to it. But if you need my code anyway, please tell and I'll put it here.

Sorry for my English.

== EDIT == here is my root urls.py file:

from django.conf.urls import patterns, url, include

from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns('',
    url(r'^polls/', include('polls.urls', namespace="polls")),
    url(r'^admin/', include(admin.site.urls)),
)

and this is polls/views.py:

from django.shortcuts import render, get_object_or_404
from django.http import HttpResponse, HttpResponseRedirect
from django.core.urlresolvers import reverse

from polls.models import Choice, Poll

# Create your views here.
def index(request):
    latest_poll_list = Poll.objects.order_by('-pub_date')[:5]
    context = {'latest_poll_list': latest_poll_list }
    return render(request, 'polls/index.html', context)

def detail(request, poll_id):
    poll = get_object_or_404(Poll, pk=poll_id)
    return render(request, 'polls/detail.html', {'poll':poll})

def results(request, poll_id):
    return HttpResponse("Wyniki ankiety %s!" %poll_id)

def vote(request, poll_id):
    p = get_object_or_404(Poll, pk=poll_id)
    try:
        selected_choice = p.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the poll voting form
        return render(request, 'polls/detail.html', {
            'poll':p,
            'error_message':"Nie wybrałeś żadnej opcji.",
            })
    else:
        selected_choice.votes += 1
        selected_choice.save()
    return HttpResponse(reverse('polls:results', args=(p.id,)))

polls/urls.py:

from django.conf.urls import patterns, url

from polls import views


urlpatterns = patterns('',
    # ex: /polls/
    url(r'^$', views.index, name='index'),
    # ex: /polls/5/
    url(r'^(?P<poll_id>\d+)/$', views.detail, name='detail'),
    # ex: /polls/5/results
    url(r'^(?P<poll_id>\d+)/results/$', views.results, name='results'),
    # ex: /polls/5/vote
    url(r'^(?P<poll_id>\d+)/vote/$', views.vote, name='vote'),
)

UPDATE: Okay, I've made a foolish mistake by placing my urls.py in the wrong directory.. sorry

Answer 1

Yes, namespace issue for me as well - the above response helped me!

Really important to make sure you are in /polls not /admin/polls when you are inputting your server link on the browser.

Also, this works in path as well.

For mysite/polls/urls - please add the below line of code

app_name = 'polls'

and then also your mysite/mysite/urls should look like below:

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

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

Answer 2

you should add app name as like below in polls/urls.py, I had the same issue but solved it by adding this:

app_name = 'polls'