Validator for a range of values using Voluptuous

validators.py

class Range:
    """A validator to check if a value is within a range."""

    def __init__(self, start, stop=None, step=1):
        # Do our best to match range's signature.
        if stop is None:
            # If there is no value for stop, use start as stop instead.
            self.range = range(start)
        else:
            self.range = range(start, stop, step)

    def __call__(self, other):
        return other in self.range

if __name__ == '__main__':
    from voluptuous import Schema
    schema = Schema(Range(10))
    for x in range(10):
        assert schema(x)
    assert not schema(10)

    schema = Schema(Range(10, 100, 5))
    for x in range(10, 100, 5):
        assert schema(x)
    assert not schema(9)
    assert not schema(11)
    assert not schema(101)