Robert Collins added the comment: Future direction: hamcrest style matchers. You can read more about them in the context of unittest https://rbtcollins.wordpress.com/2010/05/10/maintainable-pyunit-test-suites/ and http://testtools.readthedocs.io/en/latest/for-test-authors.html#matchers - sorry about the formatting in the blog post, wordpress changed theme details some time after I wrote the post and it now renders horribly :(.
w.r.t. error messages, a regular function that raises AssertionError with a nice message will be precisely as usable. def assert_math_isclose(first, second, rel_tol=1e-09, abs_tol=0.0, msg=None): if math.isclose(first, second, rel_tol=rel_tol, abs_tol=abs_tol): return standardMsg = ('%s != %s with relative tolerance of %.3g' ' and absolute tolerance of %.3g' % (safe_repr(first), safe_repr(second), rel_tol, abs_tol)) if msg: raise AssertionError("{} : {}".format(standardMsg, msg)) else: raise AssertionError(standardMsg) The reason I'm pushing back on adding methods to TestCase is that every one we add collides with some number of subclasses out in the wild: the TestCase class has multiple distinct APIs in the same namespace - and thats very poor for maintaining compatibility. Long term I want to have entirely separate interfaces for these things, but thats even more radical an overhaul than adding matchers as a stock facility, and I don't currently have a planned timeline for starting on that. All of that said, I see that this isn't the same as assertAlmostEqual in mathematical terms - but in /user/ terms I think it is. So why can't we make assertAlmostEqual be this? Just add the extra parameter needed with a default value and change the implementation? ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue27198> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com