def one(self):
        ret = list(self)

        l = len(ret)
        if l == 1:
            return ret[0]
        elif l == 0:
            raise orm_exc.NoResultFound("No row was found for one()")
        else:
            raise orm_exc.MultipleResultsFound(
                "Multiple rows were found for one()")
Return exactly one result or raise an exception.
dataset/ETHPy150Open goFrendiAsgard/kokoropy/kokoropy/packages/sqlalchemy/orm/query.py/Query.one