Osh (Object SHell) is a scripting tool I wrote for working with clusters and databases. I just released version 0.9.1. It's based on the idea of piping Python objects from one command to another. Python functions can be used to filter and transform objects. Rows from a database query turn into Python tuples. Commands can be run locally, or on all nodes of a cluster in parallel. You can use osh from the command-line, but it also has a Python API for use within Python scripts.
Osh is three years old and pretty stable, and I use it routinely for working on clusters in my work at Hitachi Data Systems. More information on osh can be found here.