文档地址http://docs.python.org/library/unittest.html
第一个例子直接引用文档中的例子，其他的简略的写了写结论性的东西，具体的参考python_testing_cookbook一书。
一、简单的例子
View Code
1 import random
2 import unittest
3
4 class TestSequenceFunctions(unittest.TestCase):
5
6 def setUp(self):
7 self.seq = range(10)
8
9 def test_shuffle(self):
10 # make sure the shuffled sequence does not lose any elements
11 random.shuffle(self.seq)
12 self.seq.sort()
13 self.assertEqual(self.seq, range(10))
14
15 # should raise an exception for an immutable sequence
16 self.assertRaises(TypeError, random.shuffle, (1,2,3))
17
18 def test_choice(self):
19 element = random.choice(self.seq)
20 self.assertTrue(element in self.seq)
21
22 def test_sample(self):
23 with self.assertRaises(ValueError):
24 random.sample(self.seq, 20)
25 for element in random.sample(self.seq, 5):
26 self.assertTrue(element in self.seq)
27
28 if __name__ == '__main__':
29 unittest.main()
实现一个继承unittest.TestCase的类，使用unittest.main()来测试该类中所有以test开头的测试用例。
简单的assert方法有如下：
self.assertEquals(100, value)
self.assertTrue(value == 0)
self.assertFalse(value > 0
self.assertRaises(TypeError, value.convert_to_decimal)
在写测试用例的时候尽量使用assertEquals而不是assertTrue、assertFalse，当assertEquals失败的时候，会打印出比较的两方值更直观
self.fail([msg])会无条件的导致测试失败，不推荐使用。
下面的例子的写法是要避免发生：
View Code
1 import unittest
2 class BadTest(unittest.TestCase):
3 def test_no_roman_numeral(self):
4 value = RomanNumeralConverter(None)
5 try:
6 value.convert_to_decimal()
7 self.fail("Expected a TypeError")
8 except TypeError, e:
9 pass
这个时候推推荐使用assertRaises
二、使用setUp和tearDown
每次运行test方法时，先用setUp初始化程序，然后运行test方法，最后使用tearDown清理程序
def setUp(self):
print "Creating a new RomanNumeralConverter..."
self.cvt = RomanNumeralConverter()
def tearDown(self):
print "Destroying the RomanNumeralConverter..."
self.cvt = None
如果不同的方法需要不同的setUp和tearDown方法，那么只好写过个测试用例了。
三、使用比unittest.main()更详细的运行测试用例的方法
if __name__ == "__main__":
suite = unittest.TestLoader().loadTestsFromTestCase( \
RomanNumeralConverterTest)
unittest.TextTestRunner(verbosity=2).run(suite）
python使用unittest.TestLoader().loadTestsFromTestCase方法获取RomanNumeralConverterTest的所有test方法
然后通过TextTestRunner来运行
四、运行部分测试方法
View Code
1 if __name__ == "__main__":
2 import sys
3 suite = unittest.TestSuite()
4 if len(sys.argv) == 1:
5 suite = unittest.TestLoader().loadTestsFromTestCase(\
6 RomanNumeralConverterTest)
7 else:
8 for test_name in sys.argv[1:]:
9 suite.addTest(\
10 RomanNumeralConverterTest(test_name))
11 unittest.TextTestRunner(verbosity=2).run(suite)
五、一次运行多个测试用例
View Code
1 if __name__ == "__main__":
2 import unittest
3 from recipe5 import *
4 suite1 = unittest.TestLoader().loadTestsFromTestCase( \
5 RomanNumeralConverterTest)
6 suite2 = unittest.TestLoader().loadTestsFromTestCase( \
7 RomanNumeralComboTest)
8 suite = unittest.TestSuite([suite1, suite2])
9 unittest.TextTestRunner(verbosity=2).run(suite)
六、在test model 中 使用test suites
View Code
1 def high_and_low():
2 suite = unittest.TestSuite()
3 suite.addTest(\
4 RomanNumeralConverterTest("test_parsing_millenia"))
5 suite.addTest(\
6 RomanNumeralConverterTest("test_parsing_one"))
7 return suite
8
9 def combos():
10 return unittest.TestSuite(map(RomanNumeralConverterTest,\
11 ["test_combo1", "test_combo2", "test_combo3"]))
12
13 def all():
14 return unittest.TestLoader().loadTestsFromTestCase(\
15 RomanNumeralConverterTest)
16
17 if __name__ == "__main__":
18 for suite_func in [high_and_low, combos, all]:
19 print "Running test suite '%s'" % suite_func.func_name
20 suite = suite_func()
21 unittest.TextTestRunner(verbosity=2).run(suite)
七、将已有的测试代码迁移到unittest
不使用unittest
View Code
1 from recipe7 import *
2
3 class RomanNumeralTester(object):
4 def __init__(self):
5 self.cvt = RomanNumeralConverter()
6
7 def simple_test(self):
8 print "+++ Converting M to 1000"
9 assert self.cvt.convert_to_decimal("M") == 1000
10
11 def combo_test1(self):
12 print "+++ Converting MMX to 2010"
13 assert self.cvt.convert_to_decimal("MMXX") == 2010
14
15 def combo_test2(self):
16 print "+++ Converting MMMMDCLXVIII to 4668"
17 val = self.cvt.convert_to_decimal("MMMMDCLXVII")
18 self.check(val, 4668)
19
20 def other_test(self):
21 print "+++ Converting MMMM to 4000"
22 val = self.cvt.convert_to_decimal("MMMM")
23 self.check(val, 4000)
24
25 def check(self, actual, expected):
26 if (actual != expected):
27 raise AssertionError("%s doesn't equal %s" % \
28 (actual, expected))
29
30 def test_the_system(self):
31 self.simple_test()
32 self.combo_test1()
33 self.combo_test2()
34 self.other_test()
35
36 if __name__ == "__main__":
37 tester = RomanNumeralTester()
38 tester.test_the_system()
迁移到unittest
View Code
1 from recipe7 import *
2 from recipe7_legacy import *
3 import unittest
4
5 if __name__ == "__main__":
6 tester = RomanNumeralTester()
7
8 suite = unittest.TestSuite()
9 for test in [tester.simple_test, tester.combo_test1, \
10 tester.combo_test2, tester.other_test]:
11 testcase = unittest.FunctionTestCase(test)
12 suite.addTest(testcase)
13
14 unittest.TextTestRunner(verbosity=2).run(suite)
八、简单化
一个测试函数里面写一个assert***,便于查看bug
九、测试边缘
比如测试一个到4000为止的整数，需要测试
1,4000, 0 4001, -1, None, 1.2
错误的输入也是必要的
通过迭代测试边缘
View Code
1 def test_bad_inputs(self):
2 r = self.cvt.convert_to_roman
3 d = self.cvt.convert_to_decimal
4 edges = [("equals", r, "", None),\
5 ("equals", r, "I", 1.2),\
6 ("raises", d, TypeError, None),\
7 ("raises", d, TypeError, 1.2)\
8 ]
9 [self.checkout_edge(edge) for edge in edges]
10
11 def checkout_edge(self, edge):
12 if edge[0] == "equals":
13 f, output, input = edge[1], edge[2], ed
14 print("Converting %s to %s..." % (input
15 self.assertEquals(output, f(input))
16 elif edge[0] == "raises":
17 f, exception, args = edge[1], edge[2],
18 print("Converting %s, expecting %s" % \
19 (args, exception))
20 self.assertRaises(exception, f, *args)
