requires can be a list, so you can :
db.ips.ipaddress.requires = [IS_NOT_IN_DB(db, 'ips.ipaddress')] db.ips.ipaddress.requires.append(IS_IPV4())
requires can be a list, so you can :
db.ips.ipaddress.requires = [IS_NOT_IN_DB(db, 'ips.ipaddress')] db.ips.ipaddress.requires.append(IS_IPV4())