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} doesnt 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(shouldnt 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。