On Fri, Jan 23, 2015 at 5:45 PM, Chris Angelico <rosuav@gmail.com> wrote:
Updating the assertion to use the new function would be a matter of tweaking the implementation of unittest's assertAlmostEqual() to now call this function and assert that it returns True. The OO structure of unittest wouldn't be affected; just the exact definition of one particular assertion. I'd say that's a point worth mentioning in the PEP. Conceptually, this is going to do the same thing; yes, it's a change of definition, but obviously this won't be done in a point release anyway. It would make reasonable sense to sync them up. Alternatively, if you choose not to have that as part of the proposal, it would be worth adding a word or two of docs to unittest stating that assertAlmostEqual is not the same as is_close_to (and/or add "assertCloseTo" which would use it), as the existing implementation is all about absolute difference.
Yeah, having just taken a quick look at the source, I'd go so far as to say assertAlmostEqual is almost totally broken. I had to read the docs three times to work out that while it sorta sounds like it provides relative tolerances, it actually doesn't at all -- places=3 means something like abs_tol=10**-3. Not really appropriate for numerical work. -n -- Nathaniel J. Smith Postdoctoral researcher - Informatics - University of Edinburgh http://vorpus.org