在实例化类对象之前，有没有一种方法可以引用它？

Question

我正在尝试用Python做一个简单的文本游戏。我有一个Room类：

class Room():
    def __init__(self, monster, exits, loot):
        self.room_guard = monster
        self.exits = exits
        self.guard_is_alive = True
        self.loot = loot

当我创建文件室时，出现了一个错误，因为我在创建它们之前调用它们，如下所示：

room_2 = Room(spider, {"West": room_3, "East": room_4, "South": room_1}, 2)
room_1 = Room(trogdor, {"North": room_2}, 2)

房间2不能有"South": room_1，因为它还没有被实例化。有办法吗？你知道吗

Answer 1

两个选项：间接、创建后赋值。你知道吗

不要直接引用文件室，而是使用将文件室名称映射到文件室的dict：

rooms = {}
rooms['room_2'] = Room(spider, {"West": 'room_3', "East": 'room_4', "South": 'room_1'}, 2)
rooms['room_1'] = Room(trogdor, {"North": 'room_2'}, 2)

或在创建房间对象后指定出口：

room_2 = Room(spider, {}, 2)
room_1 = Room(trogdor, {}, 2)

room_2.exits = {"West": room_3, "East": room_4, "South": room_1}
room_1.exits = {"North": room_2}