old_contents: from django.conf.urls import url
  from .views import PersonalProfile, UpdateProfile, NotificationEdit, NotificationCreate, PublicProfile
  
  urlpatterns = [
      url(r'^profile/(?P<username>[\w.@+-]+$)/$', PublicProfile.as_view(), name='public_profile'),
      url(r'^$', PersonalProfile.as_view(), name='personal_profile'),
      url(r'^edit/$', UpdateProfile.as_view(), name='update_profile'),
      url(r'^notifications/add/$', NotificationCreate.as_view(), name='notification_create'),
      url(r'^notifications/(?P<notification_id>\d+)/$', NotificationEdit.as_view(), name='notification_edit')
  ]
  
new_contents: from django.conf.urls import url
  from .views import PersonalProfile, UpdateProfile, NotificationEdit, NotificationCreate, PublicProfile
  
  urlpatterns = [
      url(r'^profile/(?P<username>[\w.@+-]+)/$', PublicProfile.as_view(), name='public_profile'),
      url(r'^$', PersonalProfile.as_view(), name='personal_profile'),
      url(r'^edit/$', UpdateProfile.as_view(), name='update_profile'),
      url(r'^notifications/add/$', NotificationCreate.as_view(), name='notification_create'),
      url(r'^notifications/(?P<notification_id>\d+)/$', NotificationEdit.as_view(), name='notification_edit')
  ]
  
subject: fix url regexp for user profiles