old_contents: from django.conf.urls import url
  
  from . import views
  
  app_name = 'news'
  urlpatterns = [
  	url(r'^$', views.ArticleListView.as_view(), name='article-list'),
  	url(r'^article/(?P<slug>[-\w]+)/$', views.ArticleDetailView.as_view(), name='article-detail'),
      url(r'^article/(?P<slug>[-\w]+)/comment$', views.comment, name='comment')
  ]
  
new_contents: from django.conf.urls import url
  
  from . import views
  
  app_name = 'news'
  urlpatterns = [
  	url(r'^$', views.ArticleListView.as_view(), name='article-list'),
  	url(r'^article/(?P<slug>[-\w]+)/$', views.ArticleDetailView.as_view(), name='article-detail'),
  	url(r'^article/(?P<slug>[-\w]+)/comment$', views.comment, name='comment')
  ]
  
subject: Update urls.py