def validate_host_address(value):
    """Validate whether ``value`` is a host IP address."""
    cidr = validate_cidr(value)
    if settings.HOST_PREFIXES not in cidr.prefixlen:
        raise exc.ValidationError({
            'address': '%r is not a valid host address!' % value
        })
    return value
dataset/ETHPy150Open dropbox/nsot/nsot/validators.py/validate_host_address/swapped operands of `not in`