On Fri, Mar 1, 2019 at 11:00 PM INADA Naoki <songofaca...@gmail.com> wrote: > > I dislike adding more operator overload to builtin types. > > str is not commutative, but it satisfies a in (a+b), and b in (a+b). > There are no loss. > > In case of dict + dict, it not only sum. There may be loss value. > > {"a":1} + {"a":2} = ? > > In case of a.update(b), it's clear that b wins. > In case of a + b, "which wins" or "exception raised on duplicated key?" is > unclear to me.
Picking semantics can be done as part of the PEP discussion, and needn't be a reason for rejecting the proposal before it's even made. We have at least one other precedent to consider: >>> {1} | {1.0} {1} >>> {1.0} | {1} {1.0} I have absolutely no doubt that these kinds of questions will be thoroughly hashed out (multiple times, even) before the PEP gets to pronouncement. ChrisA _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/