SQLObject support inherentance which could be used as follows:
class User(SQLObject):
name = StringCol()
cards = MultipleJoin("Card",joinColumn='user_id')
class Card(InheritableSQLObject):
user = ForeignKey("User")
expire = DateCol()
class BloodCard(Card):
bloodtype = EnumCol(enumValues=['A','B','AB','O'])
rhesus = BoolCol()
class IntrestCard(InheritableSQLObject):
.....
