title: Removing duplicates from Pandas dataFrame with condition for retaining original
body: <p>Assuming I have the following DataFrame:</p>
  
  <pre><code> A | B
   1 | Ms
   1 | PhD
   2 | Ms
   2 | Bs
  </code></pre>
  
  <p>I want to remove the duplicate rows with respect to column A, and I want to retain the row with value 'PhD' in column B as the original, if I don't find a 'PhD', I want to retain the row with 'Bs' in column B.</p>
  
  <p>I am trying to use</p>
  
  <pre><code> df.drop_duplicates('A') 
  </code></pre>
  
  <p>with a condition </p>