old_contents: from django.conf.urls import url
  
  from .views import api_v3_view
  
  urlpatterns = [
      url(r'^api/v3(?P<path>[a-z0-9/-]+)$', api_v3_view, name='api_v3_view'),
  ]
  
new_contents: from django.conf.urls import url
  
  from .views import api_v3_view
  
  urlpatterns = [
      url(r'^api/v3(?P<path>[a-z0-9/-]+?)/?$', api_v3_view, name='api_v3_view'),
  ]
  
subject: remove trailing slash eg. /api/v3/mimicon-2018/