On Thu, 29 Aug 2019 12:51:04 +0900 "Stephen J. Turnbull" <turnbull.stephen...@u.tsukuba.ac.jp> wrote: > > If there's a protocol for > converting objects to JSON, people will expect it to work, pretty much > as much as __str__ does, at least in the domain that they're working > in. And frequently it won't, and the user will be surprised by an > exception, possibly in production when encountering an unusual case.
There isn't a specific argument here. This is just FUD. > To me, it's analogous to the UnicodeErrors that have been the bane of > Mailman development for two decades. > Our parsers are supposed to just > work on any email message, but somehow the users keep finding new ways > to crash them. :-/ And that is related to JSON... how? > Worse, the __json__ method will *seem* to work when inherited by a > derived class, but doesn't know to serialize essential information > about that derived class. > That's an error by the programmer of the > derived class, of course, but it seems a very likely one to me. We should probably ban subclassing from Python so that you feel better. > Perhaps NumPy and Pandas converting all their types to use the > __json__ protocol will be enough that the majority of json.dumps users > will never see another such Exception, and surely no data corruption > in production. Seems unlikely to me, and the possibility of such > problems should be considered when we think about the development > burden we are imposing on library maintainers, and the risks to > downstreams, of adopting this protocol. Which "development burden" are we imposing on library maintainers? Library maintainers are free to adopt or not the __json__ protocol. There is no formal obligation. Antoine. _______________________________________________ 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/FQTJWG23MQNQK3SIBID76MJYLYGPQGRI/ Code of Conduct: http://python.org/psf/codeofconduct/
