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 included a library not (fully) django 2.1 compatible yet (django_auth_pro_saml2). Hence I create a second file saml_urls.py:

from django_saml2_pro_auth.urls import urlpatterns

app_name = 'saml'

Such that I could include the urls as:

from django.urls import include, re_path as url

urlpatterns = [
    ..., url(r'', include('your_app.saml_urls', namespace='saml')), ...
]

Hacky, but it worked for me, whereas the url(r'^reviews/', include(('reviews.urls', 'reviews'), namespace='reviews')) did not.