Python中unittest用法实例


            本文实例讲述了Python中unittest的用法，分享给大家供大家参考。具体用法分析如下：

1. unittest module包含了编写运行unittest的功能，自定义的test class都要集成unitest.TestCase类，test method要以test开头，运行顺序根据test method的名字排序，特殊方法:

① setup():每个测试函数运行前运行

② teardown():每个测试函数运行完后执行

③ setUpClass():必须使用@classmethod 装饰器,所有test运行前运行一次

④ tearDownClass():必须使用@classmethod装饰器,所有test运行完后运行一次

2. 示例代码:





#文件名runtest.py

import random

import unittest



class TestSequenceFunctions(unittest.TestCase):



  def setUp(self):

    self.seq = list(range(10))



  def test_shuffle(self):

    # make sure the shuffled sequence does not lose any elements

    random.shuffle(self.seq)

    self.seq.sort()

    self.assertEqual(self.seq, list(range(10)))



    # should raise an exception for an immutable sequence

    self.assertRaises(TypeError, random.shuffle, (1,2,3))



  def test_choice(self):

    element = random.choice(self.seq)

    self.assertTrue(element in self.seq)



  def test_sample(self):

    with self.assertRaises(ValueError):

      random.sample(self.seq, 20)

    for element in random.sample(self.seq, 5):

      self.assertTrue(element in self.seq)



if __name__ == '__main__':

  unittest.main()







3.运行方式:在命令行直接运行这个runtest.py

可以使用unitest.skip装饰器族跳过test method或者test class,这些装饰器包括:

① @unittest.skip(reason):无条件跳过测试，reason描述为什么跳过测试

② @unittest.skipif(conditition,reason):condititon为true时跳过测试

③ @unittest.skipunless(condition,reason):condition不是true时跳过测试

可以自定义skip decorator





#这是一个自定义的skip decorrator

def skipUnlessHasattr(obj, attr):

  if hasattr(obj, attr):

    return lambda func: func

  return unittest.skip("{!r} doesn't have {!r}".format(obj, attr))







skip decorator示例代码:





class MyTestCase(unittest.TestCase):



  @unittest.skip("demonstrating skipping")

  def test_nothing(self):

    self.fail("shouldn't happen")



  @unittest.skipIf(mylib.__version__ < (1, 3),

           "not supported in this library version")

  def test_format(self):

    # Tests that work for only a certain version of the library.

    pass



  @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")

  def test_windows_support(self):

    # windows specific testing code

    pass



@unittest.skip("showing class skipping")

class MySkippedTestCase(unittest.TestCase):

  def test_not_run(self):

    pass







4.expected failure:使用@unittest.expectedFailure装饰器，如果test失败了，这个test不计入失败的case数目

希望本文所述对大家Python程序设计的学习有所帮助。