title: Assigning values to duplicate row in pandas dataframe
body: <p>Exist dataframe with</p>
  
  <pre><code>Customer  Score
  3a62-4799  500
  3a62-4799   NA
  3a62-1234   450
  3a62-1234   NA
  </code></pre>
  
  <p>How to find all duplicate with customer and copy score to NA value.</p>
  
  <p>I tried this approach</p>
  
  <pre><code>X['Score'][((X.set_index('Customer').index.get_duplicates()) &amp; (X['Score']&gt;0)).any()] =X['Score']
  </code></pre>
  
  <p>But it doesn’t work</p>
  
  <blockquote>
    <p>ValueError: Arrays were different lengths:</p>
  </blockquote>