Quick Python

typing

question: I have an abstract base class

Animal

with a class property

siblings

initialised to an empty

list

class Animal(metaclass=abc.ABCMeta):
    siblings = []

and I want to use

typing

to infer the element type of

siblings

when sub-classed. Non-working example, but something like:

T = TypeVar('T', bound='Animal')

class Animal(Generic[T], metaclass=abc.ABCMeta):
    siblings: List[T] = []

class Cat(Animal[Cat]):    # class X(Y[X]) paradigm seems weird
    pass

class Dog(Animal[Dog]):
    pass

Cat.siblings    # expect type of List[Cat]
Dog.siblings    # expect type of List[Dog]