def _get_requested_networks(self, requested_networks):
        networks = []
        network_uuids = []
        for network in requested_networks:
            request = objects.NetworkRequest()
            try:
                try:
                    request.port_id = network.get('port', None)
                except ValueError:
                    msg = _("Bad port format: port uuid is "
                            "not in proper format "
                            "(%s)") % network.get('port')
                    raise exc.HTTPBadRequest(explanation=msg)
                if request.port_id:
                    request.network_id = None
                    if not utils.is_neutron():
                        # port parameter is only for neutron v2.0
                        msg = _("Unknown argument : port")
                        raise exc.HTTPBadRequest(explanation=msg)
                else:
                    request.network_id = network['uuid']

                if (not request.port_id and not
                        uuidutils.is_uuid_like(request.network_id)):
                    br_uuid = request.network_id.split('-', 1)[-1]
                    if not uuidutils.is_uuid_like(br_uuid):
                        msg = _("Bad networks format: network uuid is "
                                "not in proper format "
                                "(%s)") % request.network_id
                        raise exc.HTTPBadRequest(explanation=msg)

                # fixed IP address is optional
                # if the fixed IP address is not provided then
                # it will use one of the available IP address from the network
                try:
                    request.address = network.get('fixed_ip', None)
                except ValueError:
                    msg = (_("Invalid fixed IP address (%s)") %
                           network.get('fixed_ip'))
                    raise exc.HTTPBadRequest(explanation=msg)

                # duplicate networks are allowed only for neutron v2.0
                if (not utils.is_neutron() and request.network_id and
                        request.network_id in network_uuids):
                    expl = (_("Duplicate networks"
                              " (%s) are not allowed") %
                            request.network_id)
                    raise exc.HTTPBadRequest(explanation=expl)
                network_uuids.append(request.network_id)
                networks.append(request)
            except KeyError as key:
                expl = _('Bad network format: missing %s') % key
                raise exc.HTTPBadRequest(explanation=expl)
            except TypeError:
                expl = _('Bad networks format')
                raise exc.HTTPBadRequest(explanation=expl)

        return objects.NetworkRequestList(objects=networks)

    # NOTE(vish): Without this regex, b64decode will happily
    #             ignore illegal bytes in the base64 encoded
    #             data.
Create a list of requested networks from the networks attribute.
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/api/openstack/compute/legacy_v2/servers.py/Controller._get_requested_networks