title: Removing duplicate values from a horizontal row or string
body: <p>I have a dataset consisting of about 50,000 rows, each line (or cell) with values seperated with a comma.</p>
  
  <pre><code>item 1, item 2, item 1, item 1, item3, item 2, item 4, item3
  </code></pre>
  
  <p>the goal output is simply</p>
  
  <pre><code>item 1, item 2, item3, item 4
  </code></pre>
  
  <p>I can use excel, open office calc, notepad++, or any other freely available program (I found a javascript solution, however it was for a single string, attempting to run it 50,000 times either did not work, or would take way longer than I have, and I don't know enough JS to adjust it)</p>
  
  <p>any suggestions on how to do this?</p>
  
  <p>&lt;<em>edited to note that some items will contain spaces</em>></p>