Class _DeepIterable

src/attr/validators.py:333–358

@attrs(repr=False, slots=True, unsafe_hash=True)
class _DeepIterable:
    member_validator = attrib(validator=is_callable())
    iterable_validator = attrib(
        default=None, validator=optional(is_callable())
    )

    def __call__(self, inst, attr, value):
        """
        We use a callable class to be able to change the ``__repr__``.
        """
        if self.iterable_validator is not None:
            self.iterable_validator(inst, attr, value)

        for member in value:
            self.member_validator(inst, attr, member)

    def __repr__(self):
        iterable_identifier = (
            ""
            if self.iterable_validator is None
            else f" {self.iterable_validator!r}"
        )
        return (
            f"<deep_iterable validator for{iterable_identifier}"
            f" iterables of {self.member_validator!r}>"
        )


def deep_iterable(member_validator, iterable_validator=None):