python Python的单元测试和动态创建测试用例

Python's unittest and dynamic creation of test cases

提问by dbr

Possible Duplicate:
How to generate dynamic (parametrized) unit tests in python?

可能的重复：
如何在 python 中生成动态（参数化）单元测试？

Is there a way to dynamically create unittesttest cases? I have tried the following..

有没有办法动态创建unittest测试用例？我试过以下..

class test_filenames(unittest.TestCase):

    def setUp(self):
        for category, testcases in files.items():
            for testindex, curtest in enumerate(testcases):
                def thetest():
                    parser = FileParser(curtest['input'])
                    theep = parser.parse()
                    self.assertEquals(theep.episodenumber, curtest['episodenumber'])

                setattr(self, 'test_%s_%02d' % (category, testindex), thetest)

..which creates all the methods correctly (they show up in dir()and are callable), but unittest's test detector, nor nosetestexecutes them ("Ran 0 tests in ...")

..它正确创建了所有方法（它们出现dir()并可以调用），但是 unittest 的测试检测器，也不nosetest执行它们（“Ran 0 tests in ...”）

Since I may be asking the wrong question - what I am trying to achieve:

因为我可能问错了问题 - 我想要实现的目标：

I have a file containing test data, a list of input filenames, and expected data (simplified to episodenumberin the above code), stored in a Python dictionary. The key is the category, the value is a list of test cases, for example..

我有一个包含测试数据、输入文件名列表和预期数据（episodenumber在上面的代码中简化为）的文件，存储在 Python 字典中。键是类别，值是测试用例列表，例如..

test_cases = {}
test_cases['example_1'] = [
    {'input': 'test.01',
    'episodenumber': 1},
    {'input': 'test.02',
    'episodenumber': 2}
]

test_cases['example_2'] = [
    {'input': 'another.123',
    'episodenumber': 123},
    {'input': 'test.e42',
    'episodenumber': 32}
]

Currently I just loop over all the data, call self.assertEqualson each test. The problem is, if one fails, I don't see the rest of the failures as they are also grouped into one test, which aborts when an assertion fails.

目前我只是遍历所有数据，调用self.assertEquals每个测试。问题是，如果一个失败，我看不到其余的失败，因为它们也被分组到一个测试中，当断言失败时会中止。

The way around this, I thought, would be to (dynamically) create a function for each test case, perhaps there is a better way?

我认为解决这个问题的方法是（动态）为每个测试用例创建一个函数，也许有更好的方法？

采纳答案by David Raznick

For this you should use test generatorsin nose. All you need to do is yield a tuple, with the first being a function and the rest being the args. From the docs here is the example.

为此，您应该在鼻子中使用测试生成器。您需要做的就是产生一个元组，第一个是函数，其余的是参数。来自此处的文档是示例。

def test_evens():
    for i in range(0, 5):
        yield check_even, i, i*3

def check_even(n, nn):
    assert n % 2 == 0 or nn % 2 == 0

回答by Adrian Panasiuk

In the following solution, the class Testscontains the helper method checkand no test cases statically defined. Then, to dynamically add a test cases, I use setattrto define functions in the class. In the following example, I generate test cases test_<i>_<j>with i and j spanning [1,3] and [2,5] respectively, which use the helper method checkwith different values of i and j.

在以下解决方案中，该类Tests包含辅助方法check并且没有静态定义的测试用例。然后，为了动态添加测试用例，我使用setattr在类中定义函数。在下面的示例中，我生成test_<i>_<j>了 i 和 j 分别跨越 [1,3] 和 [2,5] 的测试用例，它们使用check具有不同 i 和 j 值的辅助方法。

class Tests(unittest.TestCase):
    def check(self, i, j):
        self.assertNotEquals(0, i-j)



for i in xrange(1, 4):
    for j in xrange(2, 6):
        def ch(i, j):
            return lambda self: self.check(i, j)
        setattr(Tests, "test_%r_%r" % (i, j), ch(i, j))

回答by Xavier Decoret

I have posted a solution to a similar question that should give you hints of how to do this. It is based on metaclass and decorators.

我已经发布了一个类似问题的解决方案，应该会给你一些关于如何做到这一点的提示。它基于元类和装饰器。

Python unittest: Generate multiple tests programmatically?

Python unittest：以编程方式生成多个测试？