title: "TypeError: 'set' object is not callable"
body: <p>I have two iPython notebook installations. One on an AWS Micro Instance, the second using Anaconda on my Macbook (OS X Yosemite).
  I encountered a difference in the way both of them handle the following code:</p>
  
  <pre><code>my_list = [1, 2, 3, 0, 5, 10, 11, 1, 5]
  your_list = [1, 2, 3, 0, 12, 13]
  my_set = set(my_list)
  your_set = set(your_list)
  print my_set
  print len(my_set)
  print len(my_list)
  </code></pre>
  
  <p>On iPython-AWS, my output is:</p>
  
  <pre><code>set([0, 1, 2, 3, 5, 10, 11])
  7
  9
  </code></pre>
  
  <p>On iPython-Macbook, my output is:</p>
  
  <pre><code>---------------------------------------------------------------------------
  TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-29-cd060f1b0bde&gt; in &lt;module&gt;()
        1 my_list = [1, 2, 3, 0, 5, 10, 11, 1, 5]
        2 your_list = [1, 2, 3, 0, 12, 13]
  ----&gt; 3 my_set = set(my_list)
        4 your_set = set(your_list)
        5 print my_set
  
  TypeError: 'set' object is not callable
  </code></pre>
  
  <p>Additionally, these are the installation details, if relevant:
  1. iPython on AWS Micro Instance: <a href="http://i.stack.imgur.com/qYrq8.png" rel="noreferrer">http://i.stack.imgur.com/qYrq8.png</a></p>
  
  <ol start="2">
  <li>iPython Notebook on Macbook - <a href="http://i.stack.imgur.com/Q6Id5.png" rel="noreferrer">http://i.stack.imgur.com/Q6Id5.png</a></li>
  </ol>
  
  <p>I cannot seem to find the reason for this difference, although I did come across many threads on Stackoverflow regarding the "TypeError: 'set' object is not callable" issue.
  I will appreciate any help in understanding why this is so, and if there is anything I can do to ensure my code runs on both installations.</p>