title: Trying to concat a string and an int in another column
body: <p>I have a problem trying to create a column that is based on another 2 columns.</p>
  <p>So I have a dataframe that looks like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>ID</th>
  <th>Number</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>18957585-4</td>
  <td>3</td>
  </tr>
  <tr>
  <td>14548291-2</td>
  <td>2</td>
  </tr>
  <tr>
  <td>13553585-8</td>
  <td>6</td>
  </tr>
  <tr>
  <td>2454841-0</td>
  <td>21</td>
  </tr>
  <tr>
  <td>48536515-6</td>
  <td>40</td>
  </tr>
  <tr>
  <td>14548291-2</td>
  <td>33</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>And I'd like to create a new column that unites these two like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>ID</th>
  <th>Number</th>
  <th>New_Column</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>18957585-4</td>
  <td>3</td>
  <td>18957585-43</td>
  </tr>
  <tr>
  <td>14548291-2</td>
  <td>2</td>
  <td>14548291-22</td>
  </tr>
  <tr>
  <td>13553585-8</td>
  <td>6</td>
  <td>13553585-86</td>
  </tr>
  <tr>
  <td>2454841-0</td>
  <td>21</td>
  <td>2454841-021</td>
  </tr>
  <tr>
  <td>48536515-6</td>
  <td>40</td>
  <td>48536515-640</td>
  </tr>
  <tr>
  <td>14548291-2</td>
  <td>33</td>
  <td>14548291-233</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I tried</p>
  <pre><code>df['New_Column'] = df['ID'] + str(df['Number'])
  </code></pre>
  <p>But that doesn't work and the result is a cell with 4 number, each number in the corner of the cell. If I double click it, it says:
  &quot; 2
  36     3
  Name: ID_Par, dtype: int64&quot;</p>
  <p>I also tried</p>
  <pre><code>df['New_Column'] = str(df['ID']) + str(df['Number'])
  </code></pre>
  <p>But that didn't work also. I got the dataframe &quot;df&quot; from an SQL query using pyodbc, if that makes a difference.</p>
  <p>I hope someone can help me, thanks</p>