title: matplotlib.pyplot: How to "save as" .csv?
body: <p>I am creating a small application using matplotlib. Ideally, the users will only see the matplotlib UI.</p>
  
  <p>I would like to allow users of the application to retrieve the data (not just a .png) using the existing save button on the matplotlib toolbar (e.g. by writing a filename with the ".csv" file extension).</p>
  
  <p>Is it possible to override/extend some matplotlib function to save the plot data in a non-supported matplotlib format? </p>
  
  <p>I'm interested in a solution even if I need to keep a copy of the data outside matplotlib.</p>
  
  <p>I'm not interested in solutions where the data is stored in a predefined path (e.g. /tmp) or stdout. </p>