text: # routes
  from django.conf.urls import url
  from library_api import views
  
  urlpatterns = [
      url(r'^api/library_api$', views.book_list),
      url(r'^api/library_api/(?P<pk>[0-9]+)$', views.book_detail),
      url(r'^api/library_api/published$', views.book_list_published)
  ]