title: How to show two figures using matplotlib?
body: <p>I have some troubles while drawing two figures at the same time, not shown in a single plot. But according to the documentation, I wrote the code and only the figure one shows.  I think maybe I lost something important. Could anyone help me to figure out? Thanks.  (The *tlist_first* used in the code is a list of data.)</p>
  
  <pre><code>plt.figure(1)
  plt.hist(tlist_first, bins=2000000, normed = True, histtype ="step", cumulative = True, color = 'g',label = 'first answer')
  plt.ylabel('Percentage of answered questions')
  plt.xlabel('Minutes elapsed after questions are posted')
  
  plt.axvline(x = 30, ymin = 0, ymax = 1, color = 'r', linestyle = '--', label = '30 min')
  plt.axvline(x = 60, ymin = 0, ymax = 1, color = 'c', linestyle = '--', label = '1 hour')
  plt.legend()
  plt.xlim(0,120)
  plt.ylim(0,1) 
  plt.show()
  plt.close() ### not working either with this line or without it
  
  plt.figure(2)
  plt.hist(tlist_first, bins=2000000, normed = True, histtype ="step", cumulative = True, color = 'g',label = 'first answer')
  
  plt.ylabel('Percentage of answered questions')
  plt.xlabel('Minutes elapsed after questions are posted')
  
  plt.axvline(x = 240, ymin = 0, ymax = 1, color = 'r', linestyle = '--', label = '30 min')
  plt.axvline(x = 1440, ymin = 0, ymax = 1, color = 'c', linestyle = '--', label = '1 hour')
  plt.legend(loc= 4)
  plt.xlim(0,2640)
  plt.ylim(0,1)
  plt.show()
  </code></pre>