[Python-ideas] Comparable exceptions

[Ionel Cristian Mărieș]

Hey everyone,

I was writing a test the other day and I wanted to assert that some
function raises some exception, but with some exact value. Turns out you
cannot compare OSError("foobar") to OSError("foobar") as it doesn't have
any __eq__. (it's the same for all exceptions?)

I think exceptions are great candidates to have an __eq__ method - they
already have a __hash__ (that's computed from the contained values) and
they are already containers in a way (they all have the `args` attribute).

Comparing exceptions in a test assertion seems like a good usecase for this.

Thanks,
-- Ionel Cristian Mărieș, blog.ionelmc.ro
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20150225/871b358f/attachment.html>