title: python pandas - return a list or a serie of values in each cell
body: <p>I have a dataframe called 'trade' such as follow:</p>
  
  <pre><code>                        high              MFE_ts
  exit_time                                       
  2000-02-01 01:00:00  1401.50 2000-02-01 01:00:00
  2000-02-01 01:30:00  1401.00 2000-02-01 01:30:00
  2000-02-01 02:00:00  1401.00 2000-02-01 01:30:00
  2000-02-01 02:30:00  1399.75 2000-02-01 02:30:00
  2000-02-01 03:00:00  1400.00 2000-02-01 02:30:00
  2000-02-01 03:30:00  1399.25 2000-02-01 03:30:00
  2000-02-01 04:00:00  1399.00 2000-02-01 03:30:00
  2000-02-01 04:30:00  1400.25 2000-02-01 03:30:00
  2000-02-01 05:00:00  1400.50 2000-02-01 03:30:00
  2000-02-01 05:30:00  1400.75 2000-02-01 03:30:00
  </code></pre>
  
  <p>I want to add a new column to the right that will contain a Serie of values that should be as follow: </p>
  
  <p>For each row take the timestamp contained in the 'MFE_ts' column and create a list of values taken from the 'high' column that will span from that timestamp to the end of the table.
  For instance in the last row, the output should be <code>= trade.loc['2000-02-01 03:30:00':, 'high']</code></p>
  
  <p>I have tried varous iteration of the following</p>
  
  <pre><code>trade[MAE_pr] = trade.loc[trade['MFE_ts']:, 'high']
  </code></pre>
  
  <p>but without success. I assume a serie or a list would be fine - i eventually want to apply a max() or min() function to that serie/list, for each cell in that new column MAE_pr.</p>