title: Split dictionary into individual columns in a df
body: <p>I have the following <code>df</code> whose values are dictionaries:</p>
  
  <pre><code>                    tests
  SO4  {'Mon': 6, 'Tues': 6, 'Wed': 7}
  CH3  {'Mon': 0, 'Tues': 8, 'Wed': 10}
  </code></pre>
  
  <p>I would like to obtain the desired output :</p>
  
  <pre><code>         0        1          2
  SO4  'Mon': 6 'Tues': 6 'Wed': 7
  CH3  'Mon': 0 'Tues': 8 'Wed': 10
  </code></pre>
  
  <p>How could I split the dictionary into individual columns?</p>
  
  <p>I have seen the columns split of strings using <code>rsplit</code> function but not sure on how to apply it in the case of dictionaries as values.</p>