On 2020-07-06, Chris Angelico wrote: > On Mon, Jul 6, 2020 at 10:11 PM Jon Ribbens via Python-list ><python-list@python.org> wrote: >> >> On 2020-07-06, Chris Angelico <ros...@gmail.com> wrote: >> > On Mon, Jul 6, 2020 at 8:36 PM Adam Funk <a24...@ducksburg.com> wrote: >> >> Is there a "bulletproof" version of json.dump somewhere that will >> >> convert bytes to str, any other iterables to list, etc., so you can >> >> just get your data into a file & keep working? >> > >> > That's the PHP definition of "bulletproof" - whatever happens, no >> > matter how bad, just keep right on going. >> >> While I agree entirely with your point, there is however perhaps room >> for a bit more helpfulness from the json module. There is no sensible >> reason I can think of that it refuses to serialize sets, for example. > > Sets don't exist in JSON. I think that's a sensible reason.
I don't agree. Tuples & lists don't exist separately in JSON, but both are serializable (to the same thing). Non-string keys aren't allowed in JSON, but it silently converts numbers to strings instead of barfing. Typically, I've been using sets to deduplicate values as I go along, & having to walk through the whole object changing them to lists before serialization strikes me as the kind of pointless labor that I expect when I'm using Java. ;-) >> Going a bit further and, for example, automatically calling isoformat() >> on date/time/datetime objects would perhaps be a bit more controversial, >> but would frequently be useful, and there's no obvious downside that >> occurs to me. > > They wouldn't round-trip without some way of knowing which strings > represent date/times. If you just want a one-way output format, it's > not too hard to subclass the encoder - there's an example right there > in the docs (showing how to create a representation for complex > numbers). The vanilla JSON encoder shouldn't do any of this. In fact, > just supporting infinities and nans is fairly controversial - see > other threads happening right now. > > Maybe what people want is a pretty printer instead? > > https://docs.python.org/3/library/pprint.html > > Resilient against recursive data structures, able to emit Python-like > code for many formats, is as readable as JSON, and is often > round-trippable. It lacks JSON's interoperability, but if you're > trying to serialize sets and datetimes, you're forfeiting that anyway. > > ChrisA -- "It is the role of librarians to keep government running in difficult times," replied Dramoren. "Librarians are the last line of defence against chaos." (McMullen 2001) -- https://mail.python.org/mailman/listinfo/python-list
