在对象中实现打包/解包 [英] Implement packing/unpacking in an object

问题描述

我有一个只包含属性的类，我想打包/解包来处理它.我应该实施什么 collections.abc 来获得这种行为?

I have a class that only contains attributes and I would like packing/unpacking to work on it. What collections.abc should I implement to get this behaviour?

class Item(object):

    def __init__(self, name, age, gender)
        self.name = name
        self.age = age
        self.gender = gender

a, b, c = Item("Henry", 90, "male")

我想避免使用 namedtuple.

推荐答案

您可以解压任何 可迭代.这意味着您需要实现 __iter__ 方法，并返回一个迭代器.在您的情况下，这可能只是:

You can unpack any Iterable. This means you need to implement the __iter__ method, and return an iterator. In your case, this could simply be:

def __iter__(self):
    return iter((self.name, self.age, self.gender))

或者，您可以将您的类设为 Iterator，然后 __iter__ 会 return self 并且你需要实现 __next__；这是更多的工作，可能不值得付出努力.

Alternatively you could make your class an Iterator, then __iter__ would return self and you'd need to implement __next__; this is more work, and probably not worth the effort.

有关详细信息，请参阅Python 的迭代器、可迭代和迭代协议究竟是什么?

根据我上面链接的问题，您还可以使用 __getitem__ 实现迭代:

Per the question I linked above, you could also implement an iterable with __getitem__:

def __getitem__(self, index):
    return (self.name, self.age, self.gender)[index]

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