[Python-Dev] Python equivalents in stdlib Was: Include datetime.py in stdlib or not? (original) (raw)

Nick Coghlan ncoghlan at gmail.com
Thu Jul 8 16:59:02 CEST 2010

On Thu, Jul 8, 2010 at 9:13 AM, Benjamin Peterson <benjamin at python.org> wrote:

2010/7/7 Nick Coghlan <ncoghlan at gmail.com>:

On Thu, Jul 8, 2010 at 7:56 AM, Michael Foord <fuzzyman at voidspace.org.uk> wrote:

Using a class decorator to duplicate each test into two test* methods sounds  like a good approach.

Note that parameterised methods have a similar problem to parameterised modules - unittest results are reported in terms of "testmodule.testclass.testfunction", so proper attribution of results in the test output will require additional work. The separate subclasses approach doesn't share this issue, since it changes the value of the second item in accordance with the module under test. A good parameterized implementation, though, gives the repr() of the parameters in failure output.

That would qualify as "additional work" if your tests aren't already set up that way (and doesn't cover the case of unexpected exceptions in a test, where the test method doesn't get to say much about the way the error is reported).

I realised during the day that my suggested approach was more complicated than is actually necessary - once the existing tests have been moved to a separate module, that test module can itself be imported twice, once with the python version of the module to be tested and once with the C version. You can then do some hackery to distinguish the test classes without having to modify the test code itself (note, the below code should work in theory, but isn't actually tested):

============= py_module_tests = support.import_fresh_module('moduletester', fresh=['modulename'], blocked=['_modulename']) c_module_tests = support.import_fresh_module('moduletester', fresh=['modulename', '_modulename'])

test_modules = [py_module_tests, c_module_tests] suffixes = ["_Py", "_C"]

for module, suffix in zip(test_modules, suffixes): for obj in module.itervalues(): if isinstance(obj, unittest,TestCase): obj.name += suffix setattr(module, obj.name, obj)

def test_main(): for module in test_modules: module.test_main()

Cheers, Nick.

-- Nick Coghlan | ncoghlan at gmail.com | Brisbane, Australia

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