On Fri, Mar 26, 2010 at 8:59 PM, Michael Foord <fuzzy...@voidspace.org.uk> wrote: > Hello all, > > A user has suggested an optional argument to > unittest.TestCase.assertAlmostEqual for specifying a maximum difference > between the expected and actual values, instead of using rounding. > > This sounds great to me as the default implementation of assertAlmostEqual > has *never* been useful to me (YMMV). In fact one of the first things I do > on setting up a test suite is provide a TestCase that overrides > assertAlmostEqual with an implementation that uses a delta rather than > rounding. > > The implementation would be effectively: > > assert abs(actual - expected) < delta > > This has the advantage that it allows things like: > > self.assertAlmostEqual(timeStamp, expected, > delta=datetime.timedelta(seconds=5)) > > The issue is this would make the signature of assertAlmostEqual (and its > negative counterpart): > > def assertAlmostEqual(self, first, second, places=7, msg=None, delta=None) > > Note that delta comes after msg, which is different to other assert methods. > To put delta before msg would be backwards incompatible with existing uses > passing arguments positionally. In Python 3.2 we can make delta a keyword > argument. Passing both places and delta would be an error (TypeError). > > Anyway, unless there are strenuous objections I intend to do this. > > All the best, > > Michael
+1, this would be very helpful to me. Geremy Condra _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
