title: How to reshape a dataframe keeping unique information?
body: <p>I have a dataframe <code>df1</code> that contains information of interactions between agents and their status.</p>
  
  <pre><code>df1
       Name1   Name2  Name1_x Y_x Name1_y Y_y
  0    Jack    John   Jack     0  John     1
  1    Sarah   Jack   Sarah    0  Jack     0
  2    Sarah   Eva    Sarah    0  Eva      1
  3    Eva     Tom    Eva      1  Tom      0
  4    Eva     John   Eva      1  John     1
  </code></pre>
  
  <p>I would like to have a dataframe with the name and the status <code>y</code>, such as</p>
  
  <pre><code>df2
       Name   Y
  0    Eva    1
  1    John   1
  2    Tom    0
  3    Sarah  0
  4    Jack   0
  </code></pre>