title: Add "number of months" column to a column that contains datetime objects
body: <p>I have the following table:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>date</th>
  <th>months to add</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>02-2022</td>
  <td>2</td>
  </tr>
  <tr>
  <td>05-2012</td>
  <td>1</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>where the &quot;date&quot; column contains datetime objects, while &quot;months to add&quot; contains integers.<br />
  I want to obtain the following series of datetime objects:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>new date</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>04-2022</td>
  </tr>
  <tr>
  <td>06-2012</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>EDIT:<br />
  It turns out this question had already been partially answered <a href="https://stackoverflow.com/a/67530305/13410195">here</a>.<br />
  I simply replaced the call to <code>progress_apply</code> (which now throws &quot;AttributeError: 'DataFrame' object has no attribute 'progress_apply') with a simple <code>apply</code>.</p>