title: Blank URL pattern in Django
body: <p>I've inherited a Django app and have noticed <code>urlpatterns += patterns('')</code> and equivalent throughout <code>urls.py</code>. </p>
  
  <p>e.g.</p>
  
  <pre><code>urlpatterns = patterns(
      '', 
      url(r'^index.html', render_index),
  )
  
  #... 
  
  urlpatterns += patterns(
      '', 
      url(r'^page.html', another_controller),
  )
  </code></pre>
  
  <p>What is this doing? Anything? </p>