sqlalchemy enum AttributeError: 'list' object has no attribute 'replace'

在column中使用Enum:

class User(Base):    __tablename__ = 'user'    USER_ROLE_CHOICES = ['SU', 'GA', 'CU']    id = Column(Integer, primary_key=True)    password = Column(String(128))    last_login = Column(DateTime)    is_superuser = Column(Boolean)    username = Column(String(30), unique=True)    first_name = Column(String(30))    last_name = Column(String(30))    email = Column(String(30))    is_staff = Column(Boolean)    is_active = Column(Boolean)    date_joined = Column(DateTime)    role = Column(Enum(USER_ROLE_CHOICES))  #AttributeError: 'list' object has no attribute 'replace'    group = relationship('UserGroup',                         secondary=user_usergroup,                         backref='user')

在stackoverflower上找了一下，发现这么用可以：

role = Column(Enum('SU', 'GA', 'CU'))