title: Get All Unique Values in a Row
body: <p>I have a DataFrame <code>df1</code> that looks like this:</p>
  
  <pre><code>A       B       C
  -----------------
  1       1       2
  2       2       3
  5       4       9
  </code></pre>
  
  <p>I want to get all the unique values in a row. For example 1 and 2 in the first row. 2, 3 in the second row. And 4, 5 and 9 in the third row.</p>
  
  <p>Result can vary, I can imagine a new column that contains a list with unique values or replacing duplicates with <code>None</code> would be also okay (or something else, maybe there is something more pythonic for this case).</p>