title: In matplotlib, how do you display an axis on both sides of the figure?
body: <p>I want to draw a plot with matplotlib with axis on both sides of the plot, similar to this plot (the color is irrelevant to this question):</p>
  
  <p><img src="https://i.stack.imgur.com/gHYKk.gif" alt="plot"></p>
  
  <p>How can I do this with <code>matplotlib</code>?</p>
  
  <p>Note: contrary to what is shown in the example graph, I want the two axis to be exactly the same, and want to show only one graph. Adding the two axis is only to make reading the graph easier.</p>