title: How to draw an alternating line with pyplot?
body: <p>I have a series of x coordinates (e.g.: 1,2,3,4) and y coordinates (e.g.: 10,20,30,40). I would like pyplot to draw a line between two consecutive points, while skipping every other line (e.g.: draw a line between (1,10) and (2,20), and a line between (3,30) and (4,40).)
  How can this be done? </p>