On 12/12/2019 8:50 AM, Arthur Pastel wrote:
Yes, it is possible. In my github repo I have an add_slots decorator that does just that. But I don't want the stdlib dataclass decorator to start returning a different class, without some serious discussion and some upsides. I don't think making __post_init__ prettier for frozen classes meets that bar. Although if there's overwhelming support for it here, I could be convinced to change my mind.On 12/12/2019 8:07 AM, Arthur Pastel wrote:On Thu, Dec 12, 2019 at 2:03 AM Eric V. Smith <e...@trueblade.com <mailto:e...@trueblade.com>> wrote: On 12/11/2019 6:36 PM, Arthur Pastel wrote: >> Add an extra hidden attribute to every instance just >> to track whether you’re inside __post_init__ so __setattr__ can check it? I don't want to add attributes that weren't defined in the class definition. Would it be okay if we create an instance attribute before calling the __init__ and then we remove it after the __post_init__ ? Then we would simply have to check for the attribute existence when checking if we raise a FrozenInstanceError.That wouldn't work if the class used __slots__. Then, in this specific case, would it be possible to add the attribute to the __slots__ in the generated class ?No, __slots__ can't be added or modified after the class exists (which is why @dataclass doesn't have an option to add __slots__). Arg, okay i didn't know.Then would it be possible to return a child class in the _process_class function ? It would then be possible to modify the slots. I'm trying to find a way around this but maybe this is not the good approach.
Eric
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