title: pandas DataFrame print index value only once
body: <pre><code>import pandas as pd
  li = [{"employee_id":1,"project_handled": "pas"},{"employee_id":1,"project_handled": "asap"},{"employee_id":2,"project_handled": "trimm"},{"employee_id":2,"project_handled": "fat"}]
  df = pd.DataFrame(li)
  df.set_index("employee_id",inplace=True)
  print(df)
  </code></pre>
  
  <p>gives:</p>
  
  <pre><code>            project_handled
  employee_id                
  1                       pas
  1                      asap
  2                     trimm
  2                       fat
  </code></pre>
  
  <p>What I want is, index values shouldn't be repeated when printing:</p>
  
  <pre><code>            project_handled
  employee_id                
  1                       pas
                         asap
  2                     trimm
                          fat
  </code></pre>
  
  <p>I want to serialise this and share as excel using DataFrame.to_excel api. And the requirement is index shouldn't repeat itself in the employee_id column.</p>