job scheduling framework?

[Chris Curvey]

Has anyone seen a simple open source job-scheduling framework written
in Python?  I don't really want to reinvent the wheel.  All I need is
the ability to set up a series of atomic "jobs" as a "stream", then
have the system execute the jobs in the stream one-at-a-time until all
the jobs in the stream are complete or one of them reports an error.

(If it tied into a really simple grid-style computing farm, that would
be worth double points!)

-Chris