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