Python实例化类时property setter未生效 坐标未转Atom对象

Molecule类的__init__方法直接对私有属性self.__coordinates赋值，跳过了coordinates属性绑定的setter转换逻辑：

• 实例化时传入坐标参数：原始列表直接存入私有属性，完全不执行格式校验、Atom实例生成的逻辑
• 实例化完成后手动给coordinates属性赋值：才会触发setter方法，走完校验、转换流程，因此只有这种场景能得到正确的Atom对象列表。

只需要调整两处代码即可：

1. 初始化方法中不要直接操作私有属性，改为给self.coordinates赋值，复用setter的转换逻辑，保证两种赋值场景走同一套处理流程
2. 给setter方法增加None值兼容处理，适配初始化时不传坐标的默认场景，避免传入None时触发列表深度校验报错。

class Molecule(object):

    def __init__(self, coordinates=None):
        # 改为调用属性setter赋值，而非直接操作私有属性
        self.coordinates = coordinates
        self.nelec = None
        self.Z = None
        self.natom = None

    @property
    def coordinates(self):
        return self.__coordinates

    @coordinates.setter
    def coordinates(self, coords: list):
        # 兼容空分子初始化的None场景
        if coords is None:
            self.__coordinates = None
            return
        depth = lambda l: isinstance(l, list) and max(map(depth, l)) + 1
        if depth(coords) != 2:
            raise Exception("Coordinates must be provided as a nested list of depth 2")
        else:
            atom_list = []
            for atom_coord in coords:
                # 原调试用print("Test")可按需删除
                atom_coord = self.__check_coord(atom_coord)
                atom_label, atom_vec = atom_coord[0], atom_coord[1:]
                atom_list.append(Atom(atom_label, atom_vec))
            self.__coordinates = atom_list

    @staticmethod
    def __check_coord(coord):
        isnumber = lambda x: (type(x) == float or type(x) == int)
        if type(coord[0]) != str:
            raise Exception("First element must a string for an atomic label")
        if len(list(filter(isnumber, coord))) != 3 and len(coord) != 4:
            raise Exception("Each coordinate must be a list of length 4 with 1 string and 3 numbers")
        coord[0] = coord[0].upper()
        return coord

修改后两种赋值方式表现完全一致：

>>> mol = Molecule([['H', 0, 1, 1], ['O', -1, 0, 0], ['H', -1, 0, 1]])
>>> mol.coordinates
[<__main__.Atom object at 0x10c62c850>, <__main__.Atom object at 0x10c62c640>, <__main__.Atom object at 0x10c62c910>]
>>> mol2 = Molecule()
>>> mol2.coordinates =[['H', 0, 1, 1], ['O', -1, 0, 0], ['H', -1, 0, 1]]
>>> mol2.coordinates
[<__main__.Atom object at 0x10c62c970>, <__main__.Atom object at 0x10c62ca30>, <__main__.Atom object at 0x10c62caf0>]

内容的提问来源于stack exchange，提问作者Kyle