title: Are python methods chainable?
body: <pre><code>s = set([1,2,3])
  </code></pre>
  
  <p>I should be elegant to do the following:</p>
  
  <pre><code>a.update(s).update(s)
  </code></pre>
  
  <p>I doesn't work as I thought make a contains <code>set([1,2,3,1,2,3,1,2,3])</code></p>
  
  <p>So I'm wandering that Does Python advocate this chainable practise?</p>