python - 将一个类的多个函数绑定(bind)到另一个类的类事件: is there a better/shorter way?

Question

我是Python新手。我正在想象一个场景，最终我将有许多子类在主 Window 类上监听同一事件。在我在主类中创建所有子类实例并从那里分配所有事件之前。但在创建了几个子类之后，该方法变得很难监督和管理。所以现在我正在考虑使用下面所示的代码。但由于我对类(class)的了解还很初级，我想知道/希望是否有更好的方法。

class Window:
    def __init__(self):
        self.on_key_press_events = []

    def extend_on_key_press(self, event_fn):
        self.on_key_press_events.append(event_fn)

    def on_key_press(self, key):
        print('a key was pressed')
        for event_fn in self.on_key_press_events:
            event_fn(key)


class Sub():
    def __init__(self, STR_sub):
        self.STR_sub = STR_sub

    def on_key_press(self, key):
        print(f'pressed {key} from Sub: {self.STR_sub}')

    def bind_events(self, win):
        win.extend_on_key_press(self.on_key_press)


class Sub2():
    def __init__(self, STR_sub):
        self.STR_sub = STR_sub

    def on_key_press(self, key):
        print(f'pressed {key} from Sub2: {self.STR_sub}')

    def bind_events(self, win):
        win.extend_on_key_press(self.on_key_press)


win = Window()

sub = Sub("sub instance of Sub")
sub.bind_events(win)

sub2 = Sub2("sub2 instance of Sub2")
sub2.bind_events(win)

win.on_key_press('A')

Answer 1

您可以将这些类传递给 Window 类吗？:

class Sub():
    def __init__(self, STR_sub='cba'):
        self.STR_sub = STR_sub

    def on_key_press(self, key):
        print(f'pressed {key} from Sub: {self.STR_sub}')


class Sub2():
    def __init__(self, STR_sub='abc'):
        self.STR_sub = STR_sub

    def on_key_press(self, key):
        print(f'pressed {key} from Sub2: {self.STR_sub}')


class Sub3():
    def __init__(self, STR_sub='?'):
        self.STR_sub = STR_sub


class Window:
    def __init__(self, send_events_to=[]):
        self.send_events_to = send_events_to

    def on_key_press(self, key):
        print('a key was pressed')
        for cls in self.send_events_to:
            send = getattr(cls, 'on_key_press', None)
            if send:
                send(key)
            else:
                print('no on_key_press method')

使用示例:

s = Sub()
s2 = Sub2()
s3 = Sub3()
w = Window(send_events_to=[s, s2, s3])
w.on_key_press('hello')

输出:

a key was pressed
pressed hello from Sub: cba
pressed hello from Sub2: abc
no on_key_press method

有一些子类化:

class BaseSub(object):
    def __init__(self, STR_sub='?'):
        self.STR_sub = STR_sub

    def on_key_press(self, key):
        print(f'pressed {key} from {self.__class__.__name__}: {self.STR_sub}')


class Sub(BaseSub, object):
    def __init__(self,*args, **kwargs):
        super().__init__(*args, **kwargs)


class Sub2(BaseSub, object):
    def __init__(self, *args, **kwargs):
        super().__init__( *args, **kwargs)

    def on_key_press(self, key):
        print(f'pressed {key} from {self.__class__.__name__} with a different method: {self.STR_sub}')


class Sub3():
    pass

class Window:
    def __init__(self, send_events_to=[]):
        self.send_events_to = send_events_to

    def on_key_press(self, key):
        print('a key was pressed')
        for cls in self.send_events_to:
            send = getattr(cls, 'on_key_press', None)
            if send:
                send(key)
            else:
                print('no on_key_press method')

s = Sub(STR_sub='abc')
s2 = Sub2(STR_sub='cba')
s3 = Sub3()
w = Window(send_events_to=[s, s2, s3])

w.on_key_press('hello')

输出:

a key was pressed
pressed hello from Sub: abc
pressed hello from Sub2 with a different method: cba
no on_key_press method