old_contents: from django.conf.urls import url
  from . import views
  
  urlpatterns = [
      url(r'^(?P<url_username>[\w.@+-]+)$',
          views.user_feed, {'page_nr': '1', 'sort': 'new'}, name='user_feed'),
      url(r'^(?P<url_username>[\w.@+-]]+)/(?P<sort>hot|new|top)$',
          views.user_feed, {'page_nr': '1'}, name='user_sort_feed'),
      url(r'^(?P<url_username>[\w.@+-]]+)/'
          '(?P<sort>hot|new|top)/(?P<page_nr>\d+)$',
          views.user_feed, name='user_feed_page'),
      url(r'^(?P<url_username>[\w.@+-]+)/settings$',
          views.user_settings, name='user_settings'),
      ]
  
new_contents: from django.conf.urls import url
  from . import views
  
  urlpatterns = [
      url(r'^(?P<url_username>[\w.@+-]+)$',
          views.user_feed, {'page_nr': '1', 'sort': 'new'}, name='user_feed'),
      url(r'^(?P<url_username>[\w.@+-]+)/(?P<sort>hot|new|top)$',
          views.user_feed, {'page_nr': '1'}, name='user_sort_feed'),
      url(r'^(?P<url_username>[\w.@+-]+)/'
          '(?P<sort>hot|new|top)/(?P<page_nr>\d+)$',
          views.user_feed, name='user_feed_page'),
      url(r'^(?P<url_username>[\w.@+-]+)/settings$',
          views.user_settings, name='user_settings'),
      ]
  
subject: fix up URLs