I'm looking for an easy-to-use graphics lib for python that can output to screen as well as pdf. So, I would use code to draw some stuff (simple prims like ovals, rectangles, lines and points) to screen and then when things look good, have it output to pdf.
Creating PDFs is always a pain, it doesn't make sense if you do not aim to lose sanity.
With that said, you are aiming to do two completely different things: when you draw to screen you draw into a raster bitmap, while PDFs are mostly dynamic, like HTML. (unlike HTML they are more prone to be the same over different platforms, but that's beside the point)
If you really want to do that, the solution might be finding something that outputs PDFs, and then showing the generated PDF on screen at every step.
I guess that's the only way to have WYSIWYG results.
Recommendations for a simple 2D graphics python library that can output to screen and pdf?