Python-使用SQLModel中的过渡状态机

Question

我想在我的SQLModel模式中使用状态计算机，但我会遇到类型错误。

class Invoice(BaseSQLModel, table=True):
  id: Optional[int] = Field(primary_key=True)
  def __init__(self):
     super().__init__()
     default_status = fsm.initial_payment_state
     self.fsm = fsm.get_payment_fsm(default_status). # Throws an error here because fsm is not an attribute of the class

是否可以声明创建列时忽略的属性？如何在此处声明FSM和状态属性？

我已经尝试过，但是当试图调用fsm.add_model（self）时，代码被卡住了

class Invoice(BaseSQLModel, table=True):
  id: Optional[int] = Field(primary_key=True)
  _fsm: "Machine" = PrivateAttr()

  def __init__(self):
     super().__init__()
     default_status = fsm.initial_payment_state
     self._fsm = fsm.get_payment_fsm(default_status)
     self._fsm.add_model(self). # Gets stuck here
    

    # Allowing me to declare additional attributes
    class Config:
        extra = Extra.allow
        arbitrary_types_allowed = True