Sort of in-between the two is [yet] another Python project, Pylons. Borrows from Rails most heavily in controller/routing/helper(prototype/scriptaculous) areas, and it's extremely flexible, supports whatever DB layer you want, template layer, and URL dispatch. It heavily uses WSGI but you can ignore that fact if you don't need or want to bother with it to start. It runs on top of Myghty which is a python port of Mason(perl) and runs some heavy sites like bittorrent.com.