[Twisted-Python] "Directory triggers" with kqueue using Twisted? (on MacOS X / FreeBSD)

Hello, recently I read something about the "kqueue" event notification mechanism built into FreeBSD and that it would allow to receive notification when filesystem contents change. Would this mechanism allow to implement a similar function as database triggers for a filesystem, i.e. write a script that does something with files that are added to, modified in or deleted from a certain directory without having to poll the filesystem all the time? Folder actions allow such things on MacOS X, but Applescript is slow and I would prefer Python anyway. ;-) If so, is there a way to write such scripts in Python using Twisted? TIA, Best regards Wolfgang Keller