""" These URL patterns are included in two different ways in the main urls.py, with an extra argument present in one case. Thus, there are two different ways for each name to resolve and Django must distinguish the possibilities based on the argument list. """ from django.conf.urls import url from .views import empty_view urlpatterns = [ url(r'^part/(?P\w+)/$', empty_view, name="part"), url(r'^part2/(?:(?P\w+)/)?$', empty_view, name="part2"), ]