My only motivation for this idea is so that I can forget about namedtuple. Thinking about it again today, I withdraw my suggestion until I one day see a need for it.
On Fri, Aug 10, 2018 at 10:14 PM Eric V. Smith <e...@trueblade.com> wrote: > On 8/10/2018 7:01 PM, Neil Girdhar wrote: > > It would be nice if dataclasses > > ( > https://docs.python.org/3/library/dataclasses.html#dataclasses.dataclass) > > had an option to make them a sequence. This would make > > > > dataclass(frozen=True, order=True, sequence=True) > > > > an optionally-typed version of namedtuple. It would almost totally > > supplant it except that namedtuples have a smaller memory footprint. > > Note that type.NamedTuple already gives you typed namedtuples. > Admittedly the feature set is different from dataclasses, though. > > > sequence would simply inherit from collections.abc.Sequence and > > implement the two methods __len__ and __getitme__. > > Unless I'm misunderstanding you, this falls in to the same problem as > setting __slots__: you need to return a new class, in this case since > you can't add inheritance after the fact. I don't think > __isinstancecheck__ helps you here, but maybe I'm missing something (I'm > not a big user of inheritance or ABCs). > > Not that returning a new class is impossible, it's just that I didn't > want to do it in the first go-round with dataclasses. > That's a fair point. I'm sure you know that your decorator could always return a new class that inherits from both Sequence and the original class. As a user of dataclass, I never assumed that it wouldn't do this. > For slots, I have a sample @add_slots() at > https://github.com/ericvsmith/dataclasses/blob/master/dataclass_tools.py. > Maybe we could do something similar with @add_sequence() and test it > out? It would have to be a little more sophisticated than @add_slots(), > since it would need to iterate over __dataclass_fields__, etc. > > I'm on vacation next week, maybe I'll play around with this. > Cool, have a great vacation. > > Eric > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > 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/8C9iVJsba5A/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > python-ideas+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. >
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