title: how to remain max column in groupby table?
body: <p>I made summarized table like below using pandas groupby function</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th></th>
  <th>I</th>
  <th>II</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>A</td>
  <td>apple</td>
  <td>3</td>
  </tr>
  <tr>
  <td></td>
  <td>banana</td>
  <td>4</td>
  </tr>
  <tr>
  <td>B</td>
  <td>dog</td>
  <td>1</td>
  </tr>
  <tr>
  <td></td>
  <td>cat</td>
  <td>2</td>
  </tr>
  <tr>
  <td>C</td>
  <td>seoul</td>
  <td>9</td>
  </tr>
  <tr>
  <td></td>
  <td>tokyo</td>
  <td>5</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I want to remain if II column has max value in each category.
  For example, in A category I want to remain banana row only because it has max value in II column.
  the result table what I want to get is like below.</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th></th>
  <th>I</th>
  <th>II</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>A</td>
  <td>banana</td>
  <td>4</td>
  </tr>
  <tr>
  <td>B</td>
  <td>cat</td>
  <td>2</td>
  </tr>
  <tr>
  <td>C</td>
  <td>seoul</td>
  <td>9</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Thanks.</p>