I cand did it.. im new at this pls explain wih this example:

_name = 'gs.pet'

_columns= {

          'pet_id': fields.char('Código', size=20, required='True'),
           'name': fields.char('Nome', size=60, required='True'),
           'owner_id':fields.many2one('gs.owner','ID_owner'),
           'register_data': fields.date('Data de Registo', required='True'),
           'gender':fields.selection([(1,'Macho'),(2,'Femea')],'Gender',required='True'),
           'born_date':fields.date('Data de Nascimento',required='True'),
           'imagemPet': fields.binary('Imagem'),
            'active': fields.boolean('Activo')
           }

_name = 'gs.owner'

_columns= {

           'owner_id': fields.one2many('gs.pet', 'owner_id','Pets'),
           'name': fields.char('Name', size=60, required='True'),
           'street':fields.char('Adress',size=60, required='True'),
           'phone':fields.char('Phone',size=15, required='True'),
           'imagemOwner': fields.binary('Imagem'),
           'active': fields.boolean('Activo')
           }

I want to list all the pets of the owner I dont know what can I do