Define defaults for subclass that uses validator of parent class?

[my1e5]

I am trying to create subclasses of a parent class which have their own default values but use the validator defined in the parent class. Is this possible? Here is a simple working example:

from attrs import define, field, validators

@define(kw_only=True)
class Vehicle:
    num_wheels: int = field(validator=validators.instance_of(int))

    @num_wheels.validator
    def validate_num_wheels(self, attribute, value) -> None:
        if value <= 0:
            raise ValueError("Must be greater than 0")

And here are some subclasses which I know don't work - but hopefully illustrate what I want to do.

@define
class Car(Vehicle):
    num_wheels: int = field(default=4) #! This doesn't work


@define
class Motorbike(Vehicle):
    @num_wheels.default #! This doesn't work either
    def default_num_wheels(self) -> int:
        return 2

I basically want to protect against a user doing Car(num_wheels=3.14) or Car(num_wheels=-1) accidently. And also have this work for Motorbike etc. But I want Car() and Motorbike() to return default values defined in the subclass. Is this possible?

[hynek]

I have answered in https://stackoverflow.com/a/78158263/476759 – tl;dr: #637, but you might get around it.