title: Extract nested JSON in pandas dataframe
body: <p>I am trying to unpack nested JSON in the following pandas dataframe:</p>
  
  <pre><code>           id                                                              info
  0           0  [{u'a': u'good', u'b': u'type1'}, {u'a': u'bad', u'b': u'type2'}]
  1           1  [{u'a': u'bad', u'b': u'type1'}, {u'a': u'bad', u'b': u'type2'}]
  2           2  [{u'a': u'good', u'b': u'type1'}, {u'a': u'good', u'b': u'type2'}]
  </code></pre>
  
  <p>My expected outcome is:</p>
  
  <pre><code>           id        type1    type2
  0           0        good     bad
  1           1        bad      bad
  2           2        good     good
  </code></pre>
  
  <p>I've been looking at other solutions including <code>json_normalize</code> but it does not work for me unfortunately. Should I treat the JSON as a string to get what I want? Or is there a more straight forward way to do this?</p>