title: Pandas read CSV with embedded JSON into dataframe
body: <p>I need to read in a CSV file with Pandas and one of the columns in the CSV is JSON data.  Once I bring in the file, however, the JSON is corrupted(?) and I cannot use <code>json_normalize()</code> on it.</p>
  <p>I can't attach the file, but here is some sample code that demonstrates the problem:</p>
  <pre><code>df = pd.DataFrame({'location_id':[1,2,3], 'visits':[{&quot;ABCD&quot;:9,&quot;DEFG&quot;:8,&quot;ASDF&quot;:6},
                                                      {&quot;XYZR&quot;:4,&quot;ABCD&quot;:4},
                                                      {&quot;ASDF&quot;:4}]})
  pd.json_normalize(df.visits)
  # OUTPUTS THE NORMALIZED JSON JUST FINE
  
  df.to_csv('test_visits.csv')
  df2 = pd.read_csv('test_visits.csv')
  pd.json_normalize(df2.visits)
  
  # RESULTS IN ERROR:
  # AttributeError: 'str' object has no attribute 'values'
  </code></pre>
  <p>Is there something I'm missing in the <code>read_csv()</code> that keeps the JSON usable?</p>
  <p>Thank you in advance.</p>