title: Matplotlib: Drawing a multple line graph in a single plot (discrete plot)
body: <p>I would like to know if there is a natural way to draw a graph that consists in a group of lines of varying length like this:</p>
  
  <pre><code>5  |   x--------x
  4  |     x-----x x--x
  3  |
  2  |           x----x
  1  |     x-----x       
  0  |_______________________________
        '      '     '     '     '
        10    20    30    40    50
  </code></pre>
  
  <p>Is the only option to do a graph per line? </p>