Apologies if this is a bit off the wall but I've only just started getting into unit testing (in Python) this morning. Would generators help you in any way? You might be able to have a generator which would yield an attribute set combination each time it is called. I'm not sure if it would still stop at the first fail but I was reading this morning that the Py.test framework utilises generators, and is apparently compatible with the python unittest module.
I could be wrong though...
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