Question

I’m following a Django tutorial and suddenly when I try to access http://127.0.0.1:8000/admin/ it gives me a TemplateSyntaxError.

TemplateSyntaxError at /admin/

Caught ViewDoesNotExist while rendering: Tried results in module polls.views. Error was: ‘module’ object has no attribute ‘results’

It highlights this line:
{% url ‘django-admindocs-docroot’ as docsroot %}

The admin page worked like a charm until I got to part 3 of the tutorial and messed with the urls, although I did it exactly like they said so I doubt it’s the problem.

urls.py:

from django.conf.urls.defaults import *

from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns('',
    (r'^polls/$', 'polls.views.index'),
    (r'^polls/(?P<poll_id>\d+)/$', 'polls.views.detail'),
    (r'^polls/(?P<poll_id>\d+)/results/$', 'polls.views.results'),
    (r'^polls/(?P<poll_id>\d+)/vote/$', 'polls.views.vote'),
    (r'^admin/', include(admin.site.urls)),
)

admin.py:

from polls.models import Poll
from polls.models import Choice
from django.contrib import admin

class ChoiceInline(admin.TabularInline):
    model = Choice
    extra = 0

class PollAdmin(admin.ModelAdmin):
    fieldsets = [
        (None, {'fields': ['question']}),
        ('Date information', {'fields': ['pub_date'], 'classes': ['collapse']}),
    ]
    inlines = [ChoiceInline]
    list_display = ('question', 'pub_date')
    list_filter = ['pub_date']
    search_fields = ['question']
    date_hierarchy = 'pub_date'

admin.site.register(Poll, PollAdmin)

views.py:

from django.http import HttpResponse
from polls.models import Poll
from django.template import Context, loader

def index(request):
    latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]
    t = loader.get_template('polls/index.html')
    c = Context({
        'latest_poll_list': latest_poll_list,
    })
    return HttpResponse(t.render(c))

def detail(request, poll_id):
    return HttpResponse("You're looking at poll %s. " % poll_id)

def vote(request, poll_id):
    return HttpResponse("You're voting on poll %s." % poll_id)

Answer 1

Caught ViewDoesNotExist while rendering: Tried results in module polls.views. 
Error was: 'module' object has no attribute 'results'

That’s pretty much all you need. Ignore the TemplateSyntaxError, it’s not related to the template at all. Django is telling you that you don’t have this:

def results(request):
    # do something

In your views.py. You’ll get ViewDoesNotExist errors outside the admin when you start writing urls and referencing functions that don’t actually exist in them, so make sure as you progress that you either ensure you have such stub functions that just return a basic 200, or you comment out those urls until you need them.

Technically speaking this is an extension of a python error. If you ran:

$ python manage.py shell
>>> from poll import views
x = views.results

You’d get an AttributeError.

Since you asked why, if you look in Django/core/urlresolvers.py you’ll see the line:

_callable_cache = {} # Maps view and url pattern names to their view functions.

So basically a cache of view mappings (urls or whatever) to functions is made in the form of a hashmap (dictionary). This is constructed by this function:

def _get_callback(self):
    if self._callback is not None:
        return self._callback
    try:
        self._callback = get_callable(self._callback_str)
    except ImportError, e:
        mod_name, _ = get_mod_func(self._callback_str)
        raise ViewDoesNotExist("Could not import %s. Error was: %s" % (
                                                            mod_name, str(e)))
    except AttributeError, e:
        mod_name, func_name = get_mod_func(self._callback_str)
        raise ViewDoesNotExist("Tried %s in module %s. Error was: %s" % (
                                                   func_name, mod_name, str(e)))
    return self._callback
callback = property(_get_callback)

Which evaluates each callback to check it exists (newlines are mine).