title: What is the alphanumeric id in a reddit URL?
body: <p>What is the <code>7n5lu</code> in the reddit URL </p>
  
  <blockquote>
    <p><a href="http://www.reddit.com/r/reddit.com/comments/7n5lu/man_can_fly_if_you_watch_one_video_in_2" rel="nofollow noreferrer">http://www.reddit.com/r/reddit.com/comments/7n5lu/man_can_fly_if_you_watch_one_video_in_2</a></p>
  </blockquote>
  
  <p>...and how is it generated?</p>
  
  <p>Update:
  @Gerald, I initially thought this is some obfuscation of the id. It is just doing the conversion from integer to a more compact representation. I am thinking, why is this being done? why not use the original integer itself!!</p>
  
  <pre><code>&gt;&gt;&gt; to36(4000)
  '334'
  &gt;&gt;&gt; to36(4001)
  '335'
  </code></pre>