old_contents: from django.conf.urls import url
  
  from . import views
  
  urlpatterns = [
          url(r'^(?P<url_username>[a-z0-9]*)$', views.user_feed, {'page_nr':'1'}, name='user_feed'),
          url(r'^(?P<url_username>[a-z0-9]*)/(?P<page_nr>\d+)$', views.user_feed, name='user_feed_page'),
  ]
  
new_contents: from django.conf.urls import url
  
  from . import views
  
  urlpatterns = [
          url(r'^(?P<url_username>\w+)$', views.user_feed, {'page_nr':'1'}, name='user_feed'),
          url(r'^(?P<url_username>\w+)/(?P<page_nr>\d+)$', views.user_feed, name='user_feed_page'),
  ]
  
subject: Fix error when usernames have capital characters