title: Merge cells in pandas if values in two column is same
body: <p>I have the following data in terms of dataframe</p>
  
  <pre><code>data = pd.DataFrame({'colA': ['a', 'c', 'a', 'e', 'c', 'c'], 'colB': ['b', 'd', 'b', 'f', 'd', 'd'], 'colC':['SD100', 'SD200', 'SD300', 'SD400', 'SD500', 'SD600']})
  </code></pre>
  
  <p>I want the output as attached
  [enter image description here][2]</p>
  
  <p>I want to achieve this using pandas dataframe in python
  Can somebody help me?</p>