@property
def buy_old_quantity(self):
    '\n        [int] 买方向昨仓\n        '
    return sum((amount for (price, amount) in self._buy_old_holding_list))
[int] 买方向昨仓
@property
def buy_old_quantity(self):
    '\n        \n        '
    return sum((amount for (price, amount) in self._buy_old_holding_list))