def square(x):
  '''
  计算平方并返回结果（下面是单元测试的格式）
  > square(2)
  > square(3)
  '''
  return x * x
if __name__ == '__main__':
  import doctest,mymath
  doctest.testmod(mymath)

def square(x):  
  return x * x

import unittest, mymath
class mathTestCase(unittest.TestCase):  
  def test_square(self):    
    self.assertEqual(mymath.square(2), 4)
    self.assertEqual(mymath.square(3), 9)
if __name__ == '__main__':
  unittest.main()

.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

F
======================================================================
FAIL: test_square (__main__.mathTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
 File "D:\projects\python\test_math.py", line 6, in test_square
  self.assertEqual(mymath.square(2), 4)
AssertionError: 1.0 != 4

----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (failures=1)