为什么在具有多重继承的 super() 时不能调用所有 __init__？

Question

显示代码：

class state():
    def __init__(self):
        print('in the state class')
        self.state = "main state"

class event():
    def __init__(self):
        print("in the event class")
        self.event = "main event"

class happystate(state,event):
    def __init__(self):
        print('in the happy state class')
        super(state,self).__init__()
        super(event,self).__init__()

happystate有两个基数class--state和event,初始化happystate.

a = happystate()
in the happy state class
in the event class

为什么不能调用状态 class？

Answer 1

如果您不在其他 类 中使用 super().__init__()，并且您有多重继承，python 将停止 运行 其他 __init__ 方法。

class state():
    def __init__(self):
        super().__init__()
        print('in the state class')
        self.state = "main state"

class event():
    def __init__(self):
        super().__init__()
        print("in the event class")
        self.event = "main event"

class happystate(state,event):
    def __init__(self):
        print('in the happy state class')
        super().__init__()

我正在添加一些参考资料：

1. From Raymond Hettinger
2. Whosebug

Answer 2

正如 MisterMiyagi 所说，super(state,self).init 并不意味着“init on the super class这是状态”，意思是“init on the super class which is in self's mro after state”。

我们可以删除class state和event中的所有super().__init__()，方法如下：

class state():
    def __init__(self):
        print('in the state class')
        self.state = "main state"

class event():
    def __init__(self):
        print("in the event class")
        self.event = "main event"

class happystate(state,event):
    def __init__(self):
        print('in the happy state class')
        super(happystate,self).__init__()
        super(state,self).__init__()

初始化 class happystate:

>>> x = happystate()
in the happy state class
in the state class
in the event class
>>> x.state
'main state'
>>> x.event
'main event'