title: Exporting superscript notation in pandas dataframe to csv or excel
body: <p>I would like to write the foll. to a csv file:</p>
  
  <pre><code>  df.loc[0] = ['Total (2000)',
                         numpy.nan,
                         numpy.nan,
                         numpy.nan,
                         2.0,
                         1.6,
                         '10^6 km^2']
  </code></pre>
  
  <p>Is there a way to do that while writing '10^6 km^2' in a format such that the 6 is a superscript to 10 and 2 is a superscript to km. If not possible in csv, can I export to excel?</p>