ImproperlyConfiguredError about app_name when using namespace in include()

Question

I am currently trying out Django. I use the namespace argument in one of my include()s in urls.py. When I run the server and try to browse, I get t

Answer 1

I am also face the same error in Django 2.2 and i solve it this way

urls.py file

urlpatterns = [
   path('publisher-polls/', include('polls.urls', namespace='publisher-polls')),
]

polls/urls.py file

app_name = 'polls'
urlpatterns = [
  path('', views.IndexView.as_view(), name='index')
]

example use of namespace in calss based view method

def get_absolute_url(self):
    from django.urls import reverse
    return reverse('polls.index', args=[str(self.id)])

example use of namespace in templates

{% url 'polls:index' %}

Here polls:index mean app_name[define in polls/urls.py file]:name[define in polls/urls.py file inside path function]

their official which is pretty good you can check for more info namespace_django_official_doc