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

Features: 

  * Auto-discovery of test modules and functions
  * Detailed info on failing assert statements
  * 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

WWW: http://pytest.org