1 """Example of Recursion and PyUnit and AssertiveProgramming and FunctionalProgramming
   2 """
   3 
   4 import unittest
   5 
   6 def fact(aNum):
   7     assert aNum >= 1 and type(aNum) == int
   8     if aNum == 1:
   9         return 1
  10     else:
  11         return aNum * fact(aNum-1)
  12 
  13 factFP = lambda n: n<=1 and 1 or factFP(n-1)*n
  14 
  15 class FactorialTest(unittest.TestCase):
  16     def test1(self):
  17         self.assertEquals(1, fact(1))
  18     def test2(self):
  19         self.assertEquals(2, fact(2))
  20         self.assertEquals(6, fact(3))
  21     def testNegativeOrFloat(self):
  22         self.assertRaises(AssertionError, fact, -2)
  23         self.assertRaises(AssertionError, fact, 1.1)
  24     def testOtherTypes(self):
  25         self.assertRaises(AssertionError, fact, 'a')
  26         
  27 if __name__=='__main__':
  28     unittest.main(argv=('','-v'))