Web2py sounds similar but you generally skp the mapping part and just name your controller files and functions according to how you want our urls structured. It works really well if ou keep our app cleanly designed and avoid the urge to do "dumb" things.
There's a little bit of "magic" getting web servers to talk to python programs but once that is set up it works similarlay to PHP. But things aren't always as simple as just dropping files in directories. A lot of add on libraries need to be installed, for example (sort of like PEAR I suppose). The one advantage of PHP is deployment ease. In all other respects python is much more pleasant, IMO.
