Function Maybe

voluptuous/validators.py:622–635

Validate that the object matches given validator or is None. :raises Invalid: If the value does not match the given validator and is not None. >>> s = Schema(Maybe(int)) >>> s(10) 10 >>> with raises(Invalid): ... s("string")

(validator: Schemable, msg: typing.Optional[str] = None)

def Maybe(validator: Schemable, msg: typing.Optional[str] = None):
    """Validate that the object matches given validator or is None.

    :raises Invalid: If the value does not match the given validator and is not
        None.

    >>> s = Schema(Maybe(int))
    >>> s(10)
    10
    >>> with raises(Invalid):
    ...  s("string")

    """
    return Any(None, validator, msg=msg)


class Range(object):