title: How can I sum value in list of dataframe
body: <p>I want to sum values in list that store in dataframe in column path_pair</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>session_id</th>
  <th>path</th>
  <th>path_pair</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>T01</td>
  <td>abc</td>
  <td>[0.03, 0.09]</td>
  </tr>
  <tr>
  <td>T02</td>
  <td>def</td>
  <td>[0.02, 0.15, 0.26]</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>So the result I want to acheive can be replace same column or create a new one it something looks like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>session_id</th>
  <th>path</th>
  <th>path_pair</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>T01</td>
  <td>abc</td>
  <td>0.12</td>
  </tr>
  <tr>
  <td>T02</td>
  <td>def</td>
  <td>0.43</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>How can I do the script?</p>