old_contents: from django.conf.urls import url
  
  import core.views
  
  urlpatterns = [
      url(r'^u/(?P<slug>[\w-\.]+)/?$', core.views.run_fn, name="run_fn"),
  ]
  
new_contents: from django.conf.urls import url
  
  import core.views
  
  urlpatterns = [
      url(r'^u/(?P<slug>[\w\-\+\.]+)/?$', core.views.run_fn, name="run_fn"),
  ]
  
subject: Add more patterns to be handled in the slug