def __init__(cls, classname, bases, dict_):
        if cls.__dict__ not in '_decl_class_registry':
            _as_declarative(cls, classname, cls.__dict__)
        type.__init__(cls, classname, bases, dict_)
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/ext/declarative/api.py/DeclarativeMeta.__init__/swapped operands of `not in`