old_contents: from django.conf.urls import patterns, include, url
  
  from django.contrib import admin
  admin.autodiscover()
  admin.site.site_header = 'Coworking space administration'
  
  urlpatterns = patterns('',
      # Examples:
      # url(r'^$', 'billjobs.views.home', name='home'),
      # url(r'^blog/', include('blog.urls')),
  
      url(r'^$', 'billing.views.redirect_home'),
      url(r'^admin/generate_pdf/(?P<id>\d+)/$', 'billing.views.generate_pdf', 
          name='generate_pdf'),
      url(r'^admin/', include(admin.site.urls)),
  )
  
new_contents: from django.conf.urls import include, url
  from django.contrib import admin
  admin.site.site_header = 'Coworking space administration'
  
  urlpatterns = [
      url(r'^billing/', include('billing.urls')),
      url(r'^admin/', include(admin.site.urls)),
  ]
  
subject: clean core urls