DevMaster.net maintains a listing of 3d engines, and those which you can use with Python can be found at
http://www.devmaster.net/engines/list.php?fid=6&sid=11
Mac users might want to take a look at Unity, which seems to be a very good 3D engine, and may be used with Boo (language with Python-like syntax).
Perhaps QGL will be listed there someday? :)
ha! I'll have to get the hang of stencil / shadow volumes first. or at least, be satisfied with an approximation...