Generic

These types are mixins that are used to create other constrained types.

InitHook

Type with special __init_hook__ method which is called on instantiation. It can be used to perform some additional checks on the value.

from valtypes.type.generic import InitHook
from valtypes.error.parsing import Base as ParsingError


class Contains42(InitHook, list[int]):
    def __init_hook__(self) -> None:
        if 42 not in self:
            raise ParsingError(f"{self} doesn't contain 42")


Contains42([41, 42, 43])  # passes
Contains42([1, 2, 3])  # raises ParsingError