old_contents: from django.conf.urls import patterns, url
  from feedback.views import leave_feedback
  
  
  urlpatterns = patterns('',
      url(r'^$', leave_feedback, name='feedback'),
  )
  
new_contents: from django.conf.urls import url
  from feedback.views import leave_feedback
  
  
  urlpatterns = [
      url(r'^$', leave_feedback, name='feedback'),
  ]
  
subject: Use list for urlpatterns