title: Dynamically add series to matplotlib
body: <p>I making an application to plot Airfoils profiles in matplotlib and I need to plot a number of profiles in the same subplot. I know how to add a fixed number of series, but not how to do it dynamically. My code for one profile is:</p>
  
  <pre><code>pts = d['AG17']
  
  fig = plt.figure()
  ax = fig.add_subplot(111, aspect='equal')
  ax.plot(pts[:, 0], pts[:, 1], '-r')
  ax.grid()
  plt.show()
  </code></pre>
  
  <p>and for example for two profiles something like</p>
  
  <pre><code>ax.plot(pts[:, 0], pts[:, 1], '-r', pts1[:, 0], pts1[:, 1], '-r')
  </code></pre>
  
  <p>but how do I do it for <code>n</code> numbers of profiles?</p>