How to use the ethtool.IFF_UP function in ethtool

def lookup(self, name):
        if encode_value(name) not in map(encode_value, ethtool.get_devices()):
            raise NotFoundError('KCHIFACE0001E', {'name': name})

        ipaddr = ''
        netmask = ''
        module = 'unknown'
        status = 'down'
        try:
            ipaddr = ethtool.get_ipaddr(encode_value(name))
            netmask = ethtool.get_netmask(encode_value(name))
            module = ethtool.get_module(encode_value(name))

            flags = ethtool.get_flags(encode_value(name))
            status = 'up' if flags & (
                ethtool.IFF_RUNNING | ethtool.IFF_UP) else 'down'
        except IOError:
            pass

        iface_type = netinfo.get_interface_type(name)

        return {
            'name': name,
            'type': iface_type,
            'status': status,
            'ipaddr': ipaddr,
            'netmask': netmask,
            'module': module,
        }

def operstate(dev):
    """Get the operstate status of a device.

    Args:
        dev (str): name of the device.

    Returns:
        str: "up" or "down"

    """
    flags = ethtool.get_flags(encode_value(dev))
    return 'up' if flags & (ethtool.IFF_RUNNING | ethtool.IFF_UP) else 'down'

def flags2str(flags):
        string = ""
        if flags & ethtool.IFF_UP:
                string += "UP "
        if flags & ethtool.IFF_BROADCAST:
                string += "BROADCAST "
        if flags & ethtool.IFF_DEBUG:
                string += "DEBUG "
        if flags & ethtool.IFF_LOOPBACK:
                string += "LOOPBACK "
        if flags & ethtool.IFF_POINTOPOINT:
                string += "POINTOPOINT "
        if flags & ethtool.IFF_NOTRAILERS:
                string += "NOTRAILERS "
        if flags & ethtool.IFF_RUNNING:
                string += "RUNNING "
        if flags & ethtool.IFF_NOARP:
                string += "NOARP "
        if flags & ethtool.IFF_PROMISC: