title: Pandas read dataframe from csv with index as string, not int
body: <p>My csv file is as following :</p>
  
  <pre><code>INDEX, VAL
  04016170,22
  04206261,11
  0420677,11
  </code></pre>
  
  <p><code>df = pd.read_csv('data.csv', index_col='INDEX')</code></p>
  
  <p>How can I force pandas to read the index as string and not as integer (to preserve the first <code>0</code>) ?</p>