Python 中的“类型错误：无法实例化抽象类”

我有一个模块fi定义了以下类：

class Asset(metaclass=abc.ABCMeta):
    pass

    @abc.abstractmethod
    def get_price(self, dt : datetime.date, **kwargs):
    ''' Nothing here yet
    '''

class CashFlows(Asset):

   def __init__(self, amounts : pandas.Series, probabilities : pandas.Series = None):
   amounts = Asset.to_cash_flows()

然后我还有另一堂课Bond(fi.Asset)里面有这个方法：

def to_cash_flows(self, notional : float = 100.0) -> fi.asset.CashFlows:
    series = pandas.Series(list_of_data, indices_of_data)
    return fi.CashFlows(series)

我收到错误TypeError: Can't instantiate abstract class CashFlows with abstract methods get_price当我打电话时to_cash_flows。我见过这个答案 https://stackoverflow.com/questions/8086826/cant-instantiate-abstract-class-with-abstract-methods-on-class-that-shouldn，但我无法将其与我当前的问题联系起来。

谢谢

Your CashFlows类需要定义一个实现get_price;它是一个抽象方法和具体子类must实施它。