title: Updating plot without having to close the window with the plot
body: <p>I have a function which creates a plot. That function is called inside a loop which updates information about objects to be drawn. After the call to draw() I ask the user to press a key. The problem I am encountering is that when I execute the program, the plot appears in a new window and the code execution stops until I close that window. It is only then when the prompt for user input is executed. How can I do it so that i don't need to close the plot, but just press enter and the plot gets updated automatically then without me having to close the window? Thank you!</p>
  
  <pre><code>def draw(self):
          #### more code
  
          fig, ax = plt.subplots()
          im = ax.imshow(p, extent=[x.min(), x.max(), y.min(), y.max()])
          ax.quiver(x[skip], y[skip], dx[skip], dy[skip])
  
          fig.colorbar(im)
          ax.set(aspect=1, title='Impulse world')
  
          print self.player
  
          circle = plt.Circle((self.player.pos_x, self.player.pos_y), radius=25, fc='w')
          plt.gca().add_patch(circle)
  
          #### more code
  
          plt.show()
  
  
  #inside a loop
  draw()
  raw_input("press enter to continue...")
  </code></pre>