python-pytest

The pytest testing tool makes it easy to write small tests, yet scales to support complex functional testing. It provides

*) auto-discovery of test modules and functions,
*) detailed info on failing assert statements (no need to remember self.assert* names)
*) modular fixtures for managing small or parametrized long-lived test resources.
*) multi-paradigm support: you can use pytest to run test suites based on unittest (or trial), nose
*) single-source compatibility from Python2.6 all the way up to Python3.4, PyPy-2.3, (jython-2.5 untested)
*) many external plugins.