I really like this idea. Once you've already decided to raise an exception, does it really cost much to try to raise a more helpful one? And helpful exception messages make programming a lot less painful, and a lot more of a joy.
On Tue, Oct 22, 2019 at 2:43 PM Mike Miller <python-id...@mgmiller.net> wrote: > > On 2019-10-18 10:23, Ricky Teachey wrote: > > but i'm -0 because i am very concerned it will not be obvious to new > learners, > > without constantly looking it up, whether adding two mappings together > would either: > > The big trade off I'm gathering from this mega-thread is that the |, |= > operators are more accurate, but less obvious to newcomers, who will first > try > +, += instead. > > I've tried them in this order myself several times over the years. > > Had an idea, why not choose the more accurate syntax: |, |= after all? > Then, to > help newcomers and forgetful pros a custom error message is implemented > for +, > +=. In pseudo C/Python, something like this: > > class dict: > > def __add__(self, other): > > if isinstance(other, dict): > raise TypeError( > 'unsupported operand type(s) for +: … ' > 'Dictionary merging leads to last-value-wins data ' > 'loss. If acceptable, use the union "|" operator.' > ) > else: > raise TypeError(std_err_msg) > > > I think it is worth it to lead the newcomer to a moment's reflection on > why > dictionary combining/merging is potentially lossy. Everyone is informed > with > the proper mental model, then on their way and left alone afterward. > > Thoughts? > -Mike > _______________________________________________ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/43T52R223GYPHIDP3CHTIS3JTQYUNCVL/ > Code of Conduct: http://python.org/psf/codeofconduct/ > > -- > > --- > You received this message because you are subscribed to a topic in the > Google Groups "python-ideas" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/python-ideas/puGRBmzVl9c/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > python-ideas+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/python-ideas/3ac803c4-f703-67bf-c4c9-a37bbe0c61d8%40mgmiller.net > . >
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