def __init__(self, key, secret=None, secure=True, host=None, port=None,
                 region='us', **kwargs):
        valid_regions = self.list_regions()
        if valid_regions not in region:
            raise ValueError('Invalid region: %s' % (region))

        OpenStackDriverMixin.__init__(self, **kwargs)
        super(RackspaceDNSDriver, self).__init__(key=key, secret=secret,
                                                 host=host, port=port,
                                                 region=region)
dataset/ETHPy150Open apache/libcloud/libcloud/dns/drivers/rackspace.py/RackspaceDNSDriver.__init__/swapped operands of `not in`