Chiming in here: dataclasses was just added to the stdlib.
I understand that record class is not the same thing, but the use cases do overlap a great deal. So I think the cord goal for anyone that wants to see this in the stdlib is to demonstrate tbat recordclass Adds significant enough value to justify something so similar. Personally, I don’t see it. -CHB On Tue, Sep 4, 2018 at 2:04 PM Zaur Shibzukhov <szp...@gmail.com> wrote: > > > --- > *Zaur Shibzukhov* > > > 2018-09-03 1:02 GMT+03:00 Wes Turner <wes.tur...@gmail.com>: > >> >> On Sunday, September 2, 2018, Zaur Shibzukhov <szp...@gmail.com> wrote: >> >>> >>> >>> --- >>> *Zaur Shibzukhov* >>> >>> >>> 2018-09-02 22:11 GMT+03:00 Wes Turner <wes.tur...@gmail.com>: >>> >>>> Does the value of __hash__ change when attributes of a recordclass >>>> change? >>>> >>> >>> Currently recordclass's __hash__ didn't implemented. >>> >> >> https://docs.python.org/3/glossary.html#term-hashable >> >> https://docs.python.org/3/reference/datamodel.html#object.__hash__ >> >> http://www.attrs.org/en/stable/hashing.html >> > > There is correction: > recordclass and it's base memoryslots didn't implement __hash__, but > memoryslots implement richcompare (almost as python's list). > >> >> >>> >>>> On Sunday, September 2, 2018, Zaur Shibzukhov <szp...@gmail.com> wrote: >>>> >>>>> As the author of `recordclass` I would like to shed some light... >>>>> >>>>> Recorclass originated as a response to the [question]( >>>>> https://stackoverflow.com/questions/29290359/existence-of-mutable-named-tuple-in-python/29419745#29419745) >>>>> on stackoverflow. >>>>> >>>>> `Recordclass` was conceived and implemented as a type that, by api, >>>>> memory and speed, would be completely identical to` namedtuple`, except >>>>> that it would support an assignment in which any element could be replaced >>>>> without creating a new instance, as in ` namedtuple`. Those. would be >>>>> almost identical to `namedtuple` and support the assignment (` >>>>> __setitem__` >>>>> / `setslice__`). >>>>> >>>>> The effectiveness of namedtuple is based on the effectiveness of the >>>>> `tuple` type in python. In order to achieve the same efficiency it >>>>> was necessary to create a type `memoryslots`. Its structure >>>>> (`PyMemorySlotsObject`) is identical to the structure of` tuple` >>>>> (`PyTupleObject`) and therefore takes up the same amount of memory as` >>>>> tuple`. >>>>> >>>>> `Recordclass` is defined on top of` memoryslots` just like >>>>> `namedtuple` above` tuple`. Attributes are accessed via a descriptor >>>>> (`itemgetset`), which supports both` __get__` and `__set__` by the element >>>>> index. >>>>> >>>>> The class generated by `recordclass` is: >>>>> >>>>> `` ` >>>>> from recordclass import memoryslots, itemgetset >>>>> >>>>> class C (memoryslots): >>>>> __slots__ = () >>>>> >>>>> _fields = ('attr_1', ..., 'attr_m') >>>>> >>>>> attr_1 = itemgetset (0) >>>>> ... >>>>> attr_m = itemgetset (m-1) >>>>> >>>>> def __new __ (cls, attr_1, ..., attr_m): >>>>> 'Create new instance of {typename} ({arg_list})' >>>>> return memoryslots .__ new __ (cls, attr_1, ..., attr_m) >>>>> `` ` >>>>> etc. following the `namedtuple` definition scheme. >>>>> >>>>> As a result, `recordclass` takes up as much memory as` namedtuple`, it >>>>> supports quick access by `__getitem__` /` __setitem__` and by attribute >>>>> name via the protocol of the descriptors. >>>>> >>>>> Regards, >>>>> >>>>> Zaur >>>>> >>>>> суббота, 1 сентября 2018 г., 10:48:07 UTC+3 пользователь Martin Bammer >>>>> написал: >>>>>> >>>>>> Hi, >>>>>> >>>>>> what about adding recordclass >>>>>> (https://bitbucket.org/intellimath/recordclass) to the collections >>>>>> module >>>>>> >>>>>> It is like namedtuple, but elements are writable and it is written in >>>>>> C >>>>>> and thus much faster. >>>>>> >>>>>> And for convenience it could be named as namedlist. >>>>>> >>>>>> Regards, >>>>>> >>>>>> Martin >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Python-ideas mailing list >>>>>> python...@python.org >>>>>> https://mail.python.org/mailman/listinfo/python-ideas >>>>>> Code of Conduct: http://python.org/psf/codeofconduct/ >>>>>> >>>>> >>> > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ > -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov
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