title: how to replace values in 2 dataframe columns based on multiple conditions?
body: <p>I'm having columns in pandas dataframe which look like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">Positive</th>
  <th style="text-align: center;">Neutral</th>
  <th style="text-align: right;">Negative</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">1</td>
  <td style="text-align: center;">0</td>
  <td style="text-align: right;">1</td>
  </tr>
  <tr>
  <td style="text-align: left;">0</td>
  <td style="text-align: center;">1</td>
  <td style="text-align: right;">0</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I want it to look like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">Positive</th>
  <th style="text-align: center;">Neutral</th>
  <th style="text-align: right;">Negative</th>
  <th style="text-align: right;">Mixed</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">0</td>
  <td style="text-align: center;">0</td>
  <td style="text-align: right;">0</td>
  <td style="text-align: right;">1</td>
  </tr>
  <tr>
  <td style="text-align: left;">0</td>
  <td style="text-align: center;">1</td>
  <td style="text-align: right;">0</td>
  <td style="text-align: right;">0</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>First, I created column called mixed based on the fact that sentence is both positive and negative. Now, since I already have column &quot;mixed&quot;, I do not need double information, so I would like to replace values in positive and negative columnwith 0 (only for mixed sentiment sentences). I've tried different variation of np.where but nothing seems to understand how to replace value in 2 columns based on condition from these 2 columns.
  Any suggestions? Thanks :)</p>