Well, ZeroDivisionError doesn't derive from ValueError, does it? So it may not be a good idea, but it's certainly a tradition. On Tuesday, May 24, 2016, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
Guido van Rossum wrote:
It's very common for modules to define their own root exception class.
And it's a nuisance when their exceptions only belong to their own private hierarchy and don't participate in any the standard classifications.
I don't think Decimal is directly to blame here, because deriving its exceptions from ArithmeticError seems like a reasonable thing to do. What *doesn't* seem reasonable to me is that ArithmeticError doesn't derive from ValueError. So far nobody has explained why that's a good idea.
-- Greg _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
-- --Guido (mobile)