Hi, first post here. My two cents:
Here's a list of "prior arts" that I have collected over the years, besides attrs, that address similar needs (and often, much more): - https://github.com/bluedynamics/plumber - https://github.com/ionelmc/python-fields - https://github.com/frasertweedale/elk - https://github.com/kuujo/yuppy Regarding the name, 'dataclass', I agree that it can be a bit misleading (my first idea of a "dataclass" would be a class with only data and no behaviour, e.g. a 'struct', a 'record', a DTO, 'anemic' class, etc.). Scala has 'case classes' with some similarities ( https://docs.scala-lang.org/tour/case-classes.html). Regards, S. On Fri, Sep 8, 2017 at 4:57 PM, Eric V. Smith <e...@trueblade.com> wrote: > I've written a PEP for what might be thought of as "mutable namedtuples > with defaults, but not inheriting tuple's behavior" (a mouthful, but it > sounded simpler when I first thought of it). It's heavily influenced by the > attrs project. It uses PEP 526 type annotations to define fields. From the > overview section: > > @dataclass > class InventoryItem: > name: str > unit_price: float > quantity_on_hand: int = 0 > > def total_cost(self) -> float: > return self.unit_price * self.quantity_on_hand > > Will automatically add these methods: > > def __init__(self, name: str, unit_price: float, quantity_on_hand: int = > 0) -> None: > self.name = name > self.unit_price = unit_price > self.quantity_on_hand = quantity_on_hand > def __repr__(self): > return f'InventoryItem(name={self.name!r},unit_price={self.unit_pri > ce!r},quantity_on_hand={self.quantity_on_hand!r})' > def __eq__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) == ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > def __ne__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) != ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > def __lt__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) < ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > def __le__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) <= ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > def __gt__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) > ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > def __ge__(self, other): > if other.__class__ is self.__class__: > return (self.name, self.unit_price, self.quantity_on_hand) >= ( > other.name, other.unit_price, other.quantity_on_hand) > return NotImplemented > > Data Classes saves you from writing and maintaining these functions. > > The PEP is largely complete, but could use some filling out in places. > Comments welcome! > > Eric. > > P.S. I wrote this PEP when I was in my happy place. > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: https://mail.python.org/mailman/options/python-dev/sfermigie > r%2Blists%40gmail.com > -- Stefane Fermigier - http://fermigier.com/ - http://twitter.com/sfermigier - http://linkedin.com/in/sfermigier Founder & CEO, Abilian - Enterprise Social Software - http://www.abilian.com/ Chairman, Free&OSS Group / Systematic Cluster - http://www.gt-logiciel-libre.org/ Co-Chairman, National Council for Free & Open Source Software (CNLL) - http://cnll.fr/ Founder & Organiser, PyData Paris - http://pydata.fr/ --- “You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.” — R. Buckminster Fuller
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