title: Comparing local csvs to write updates, list(set()) issue
body: <p>I have a funny problem. I can get the unique rows in the two comparison csv files by using:</p>
  
  <pre><code>update = list(set(compareNew) - set(compareOld))
  </code></pre>
  
  <p>However, when I include this line in my function I get <em>TypeError:'list' object is not callable.</em> </p>
  
  <p>I need to do this for a few hundred csv's so I am calling the above line in a loop. Does that change anything for the function?   </p>
  
  <p>Using python 3.4      </p>