title: Why do I keep getting django.core.exceptions.ImproperlyConfigured: Specifying a namespace although I added app name in urls.py
body: <p>I have recently created a new app called newsletters, I have included it in the settings base.py and add it in the Main urls.py along with the app urls.py and added the app name as well, but i keep getting </p>
  
  <pre><code>django.core.exceptions.ImproperlyConfigured: Specifying a namespace in include() without providing an app_name is
   not supported. Set the app_name attribute 
  in the included module, or pass a 2-tuple containing the list of patterns and app_name instead.
    File "&lt;frozen importlib._bootstrap&gt;", line 975, in _find_and_load_unlocked
  </code></pre>
  
  <p>I am not sure the reason here is the settings base.py</p>
  
  <pre><code>INSTALLED_APPS = [
      'newsletters',
  ]
  </code></pre>
  
  <p>Here is the main urls.py </p>
  
  <pre><code>urlpatterns = [
      path('newsletters/', include('newsletters.urls', namespace='newsletters')),
  ]
  </code></pre>
  
  <p>Here is the newseltters app urls.py</p>
  
  <pre><code>from .views import newsletter_signup, newsletter_unsubscribe
  
  app_name = 'newsletters'
  
  urlpatterns = [
      path('signup/', include(newsletter_signup, namespace='newsletters')),
      path('unsubscribe/', include(newsletter_unsubscribe, namespace='unsubscribe')),
  </code></pre>