title: Markers as "list" in python scatter plot
body: <p>I'm trying to create a scatter plot where the markers are not all the same but 
  are numbers in sequential order.</p>
  
  <p>let's have, for instance, this code</p>
  
  <pre><code>x = numpy.random.rand(10)
  y = numpy.random.rand(10)
  
  plt.scatter(x,y)
  </code></pre>
  
  <p>this will display all equal markers on the plot.</p>
  
  <p>I would like to display numbers instead of the same marker, in sequential order.</p>
  
  <p>Specifically I would like to display for the points</p>
  
  <p>x[0],y[0] --> number 1</p>
  
  <p>x[1],y[1] --> number 2</p>
  
  <p>x[2],y[2] --> number 3</p>
  
  <p>and so on... </p>
  
  <p>Can you help me to do this?</p>
  
  <p>thanks</p>