methods of unit testing in python

gistfile1.py

# Taken from http://artifex.org/~hblanks/talks/2011/pep20_by_example.html
################################### 7 ##################################

""" Write out the tests for a factorial function. """

#-----------------------------------------------------------------------

def factorial(n):
    """
    Return the factorial of n, an exact integer >= 0.

    >>> [factorial(n) for n in range(6)]
    [1, 1, 2, 6, 24, 120]

    >>> factorial(30)
    265252859812191058636308480000000L

    >>> factorial(-1)
    Traceback (most recent call last):
        ...
    ValueError: n must be >= 0
    """
    pass

if __name__ == '__main__' and '--test' in sys.argv:
    import doctest
    doctest.testmod()

#-----------------------------------------------------------------------

import unittest

def factorial(n):
    pass

class FactorialTests(unittest.TestCase):
    def test_ints(self):
        self.assertEqual(
            [factorial(n) for n in range(6)], [1, 1, 2, 6, 24, 120])

    def test_long(self):
        self.assertEqual(
            factorial(30), 265252859812191058636308480000000L)

    def test_negative_error(self):
        with self.assertRaises(ValueError):
            factorial(-1)

if __name__ == '__main__' and '--test' in sys.argv:
    unittest.main()

#-----------------------------------------------------------------------

print 'Readability counts.'

Taken from a nice example of 'pythonic' style at http://artifex.org/~hblanks/talks/2011/pep20_by_example.html