python - 为类(class)定制双星运营商？

Question

如何实现自定义双星运算符 (**) 进行解包，类似于 __iter__ 与单星运算符 (*) 的工作方式)?

例如:

class PlayerManager(object):

    def __init__(self, players=None):
        self.players = players or []

    # Made up method to support ** operator
    def __dict_iter__(self):
        for player in self.players:
            yield get_steamid(player), player

def print_players(**players):
    print(players)

player_manager = PlayerManager([list, of, players])
print_players(**player_manager)

输出:

{
    'STEAM_0:0:02201': <Player object at 0x0000000000>,
    'STEAM_0:0:10232': <Player object at 0x0000000064>,
    'STEAM_0:0:73602': <Player object at 0x0000000128>
}

Answer 1

正如@ShadowRanger 所说，实现映射。这是一个例子:

from collections.abc import Mapping

class Foo(Mapping):
    def __iter__(self):
        yield "a"
        yield "b"

    def __len__(self):
        return 2

    def __getitem__(self, item):
        return ord(item)

f = Foo()

print(*f)
print(dict(**f))

程序输出:

a b
{'a': 97, 'b': 98}