unittest wart/bug for assertNotEqual

Zac Burns zac256 at gmail.com
Tue Oct 20 23:45:49 CEST 2009

> I was with you right up to the last six words.
> Whether it's worth changing assertNotEqual to be something other than an
> alias of failIfEqual is an interesting question. Currently all the
> assert* and fail* variants are aliases of each other, which is easy to
> learn. This would introduce a broken symmetry, where assertNotEqual tests
> something different from failIfEqual, and would mean users have to learn
> which assert* methods are aliases of fail* methods, and which are not.
> I'm not sure that's a good idea.
> After all, the documentation is clear on what it does:
>     |  assertNotEqual = failIfEqual(self, first, second, msg=None)
>     |      Fail if the two objects are equal as determined by the '=='
>     |      operator.
>     |
> (Taken from help(unittest).)
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list

My preference would be that failIfEqual checks both != and ==. This is
practical, and would benefit almost all use cases. If "!=" isn't "not
==" (IEEE NaNs I hear is the only known use case) then those could
simply not use this method.

It would not surprise me if changing this would bring to light many
existing bugs.

Zachary Burns
Aim - Zac256FL
Production Engineer (Digital Overlord)
Zindagi Games

More information about the Python-list mailing list