三言两语聊Python模块–单元测试模块unittest

实际上unittest模块才是真正意义上的用于测试的模块，功能强大的单元测试模块。

继续使用前面的例子：

# splitter.py
def split(line, types=None, delimiter=None):
    """Splits a line of test and optionally performs type conversion.
    For example:

    >>> split('GOOD 100 490.50')
    ['GOOD', '100', '490.50']
    >>> split('GOOD 100 490.50', [str, int, float])
    ['GOOD', 100, 490.50]
    >>>
    By default, splitting is perfomed on whitespace, but a different delimiter
    can be selected with the delimiter keyword argument:

    >>> split('GOOD, 100, 490.50', delimiter=',')
    ['GOOOD', '100', '490.50']
    >>>
    """

    fields = line.split(delimiter)
    if types:
        fields = [ty(val) for ty, val in zip(types, fields)]
    return fields

if __name__ == '__main__':
    # test myself
    import doctest
    doctest.testmod()

编写测试该函数的脚本：

# testsplitter.py
import splitter
import unittest

# unit test
class TestSplitFunction(unittest.TestCase):
    def setUp(self):
        pass
    def tearDown(self):
        pass
    def testsimplestring(self):
        r = splitter.split('GOOD 100 490.50')
        self.assertEqual(r, ['GOOD', '100', '490.50'])
    def testypeconvert(self):
        r = splitter.split('GOOD 100 490.50', [str, int, float])
        self.assertEqual(r, ['GOOD', 100, 490.50])
    def testdelimiter(self):
        r = splitter.split('GOOD, 100, 490.50', delimiter=',')
        self.assertEqual(r, ['GOOD', '100', '490.50'])

# Run unit test
if __name__ == '__main__':
    unittest.main()

运行结果：

>>>
F..
======================================================================
FAIL: testdelimiter (__main__.TestSplitFunction)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\Administrator\Desktop\Python Scripts\testsplitter - 副本.py", line 19, in testdelimiter
    self.assertEqual(r, ['GOOD', '100', '490.50'])
AssertionError: Lists differ: ['GOOD', ' 100', ' 490.50'] != ['GOOD', '100', '490.50']

First differing element 1:
 100
100

- ['GOOD', ' 100', ' 490.50']
?           -       -

+ ['GOOD', '100', '490.50']

----------------------------------------------------------------------
Ran 3 tests in 0.059s

FAILED (failures=1)
Traceback (most recent call last):
  File "C:\Users\Administrator\Desktop\Python Scripts\testsplitter - 副本.py", line 23, in <module>
    unittest.main()
  File "D:\Python33\lib\unittest\main.py", line 125, in __init__
    self.runTests()
  File "D:\Python33\lib\unittest\main.py", line 267, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: True

unittest里面unitest.TestCase实例t最常用的方法：

t.setUp() - 执行测试前的设置步骤

t.tearDown() - 测试完，执行清除操作

t.assertEqual(x, y [,msg]) - 执行断言

还有其他各种断言。