title: Count the number of clients that have bought in different stores in my dataframe
body: <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>client</th>
  <th>product</th>
  <th>store</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>001</td>
  <td>toy1</td>
  <td>10</td>
  </tr>
  <tr>
  <td>001</td>
  <td>toy2</td>
  <td>20</td>
  </tr>
  <tr>
  <td>003</td>
  <td>toy3</td>
  <td>10</td>
  </tr>
  <tr>
  <td>004</td>
  <td>toy4</td>
  <td>40</td>
  </tr>
  <tr>
  <td>001</td>
  <td>toy4</td>
  <td>30</td>
  </tr>
  <tr>
  <td>004</td>
  <td>toy4</td>
  <td>50</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>What I need to do it´s to count the number of clients that have bought in one store, two stores, three stores and more, something like this.</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>one store</th>
  <th>two stores</th>
  <th>three stores</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>1</td>
  <td>1</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>The purpose of this I´ts to count how many clients buy in different stores, It´s there anyway to this with python?.</p>