title: Python extend with an empty list bug?
body: <p>Why does python 2.5.2 have the following behavior</p>
  
  <pre><code>&gt;&gt;&gt;[2].extend([]) == [2]
  False
  
  &gt;&gt;&gt; [2].extend([]) == None
  True
  
  $ python --version
  Python 2.5.2
  </code></pre>
  
  <p>I assume I'm not understanding something here, but intuitively I'd think that [2].extend([]) should yield [2]</p>