Constrained types in python

collections.py

class NonEmptyList(list, Generic[T]):
    def __init__(self, *members: T):
        super().__init__([*members])
        self._validate_constraints()

    def _validate_constraints(self):
        if len(self) < 1:
            raise RuntimeError("NonEmptyList must have at least one member")

numbers.py

class PositiveInteger(int):
    def __init__(self, value):
        super().__init__()
        if self <= 0:
            raise RuntimeError("Positive integers must be positive")
        if float(self) != float(value):
            raise RuntimeError(f"{value} is not an integer")


class PositiveFloat(float):
    def __init__(self, value):
        super().__init__()
        if self <= 0:
            raise RuntimeError("Positive floats must be positive")
        if float(self) != float(value):
            raise RuntimeError(f"{value} is not a valid float")