old_contents: from django.conf.urls import patterns, url
  
  from .views import PostListView, PostDetailView
  
  urlpatterns = patterns('',
      url(r'(?P<pk>\d+)/$', PostDetailView.as_view(), name='detail'),
      url(r'/$', PostListView.as_view(), name='list'),
  )
  
new_contents: from django.conf.urls import patterns, url
  
  from .views import PostListView, PostDetailView
  
  urlpatterns = patterns('',
      url(r'(?P<pk>\d+)/$', PostDetailView.as_view(), name='detail'),
      url(r'$', PostListView.as_view(), name='list'),
  )
  
subject: Fix urls in example project