Post processing contour plot, how?

[Martin Schöön]

I am interested in creating contours but not for printing or
including in a report as an illustration. I want to go on
working on a numerical representation of the contours.

Creating contour plots using matplotlib is a breeze but I fail
to find a way to export the contours thus created in a numerical
format. Scilab has such a function but I try to reduce the number
of tools I use and I try to focus on Python.

So, I could write my own find-contours algorithm but I think
there should be a way of extracting the contours created by
matplotlib even if I have failed to find out how.

Does anyone know how to do this?

I have found one very manually involved way starting with
saving the figure in svg format and the open that file in
a text editor.

/Martin