title: MongoDB: Split multi-serie in multiple columns
body: <p>I have loaded a set of tweet in a MongoDB DB, and calculated the number of tweets grouped per month per User.</p>
  <p>I have a list as below:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>_id</th>
  <th>User</th>
  <th>Month</th>
  <th>NbTweet</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>User1</td>
  <td>1</td>
  <td>10</td>
  </tr>
  <tr>
  <td>2</td>
  <td>User1</td>
  <td>2</td>
  <td>20</td>
  </tr>
  <tr>
  <td>3</td>
  <td>User2</td>
  <td>1</td>
  <td>15</td>
  </tr>
  <tr>
  <td>4</td>
  <td>User2</td>
  <td>2</td>
  <td>25</td>
  </tr>
  <tr>
  <td>5</td>
  <td>User3</td>
  <td>1</td>
  <td>12</td>
  </tr>
  <tr>
  <td>6</td>
  <td>User3</td>
  <td>2</td>
  <td>22</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>but I would like to get the data in that form to draw a multi line chart with Matplotlib:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>_month</th>
  <th>User1</th>
  <th>User2</th>
  <th>User3</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>10</td>
  <td>15</td>
  <td>12</td>
  </tr>
  <tr>
  <td>2</td>
  <td>20</td>
  <td>25</td>
  <td>22</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Should the transformation happen in MongoDB as a pipeline, or is there any way with Pandas to transform the data ?</p>
  <p>THANKS,</p>
  <p>MadSurfer</p>