问题

我有两个类（Table 和 Button）继承自同一个类 Widget。两个子类都有它们自己的 keyEvent() 方法，并在必要时调用 Widget.keyEvent()。我想以相同的方式修改两个类的 keyEvent() 行为（例如使 `A` 和 `D` 键触发 `LEFT` 和 `RIGHT` 键）。

这段代码正如我所想：

```python
class KeyModifier:
    def keyEvent():
        # 一些代码行
        super().keyEvent()

class MyTable(KeyModifier,Table):
    pass

class MyButton(KeyModifier,Button):
    pass

但 Pylance 生气了，因为 KeyModifier.super() 没有任何 keyEvent() 方法（这是正确的）。

有没有更好的方法？另外，我希望在将 KeyModifier 与未继承自 Widget 的东西一起使用时，Pylance 能提醒我。

这个示例来自一个 PyQT 应用程序，但问题更为一般。

编辑：
将 KeyModifier 设为 Widget 的子类会导致 KeyModifier.super().keyEvent() 调用 Widget.keyEvent()，而我想调用子类方法（Table.keyEvent() 或 Button.keyEvent()）。

<details>
<summary>英文:</summary>

I have two classes (Table and Button) inherited from the same class Widget. Both subclasses have their own keyEvent() methods and both call Widget.keyEvent() when necessary. I want to modify the keyEvent() behaviour for both classes in the same way (for example make `A` and `D` keys to trigger `LEFT` and `RIGHT` keys).

This code works exactly as I want

```python
class KeyModifier:
    def keyEvent():
        # some lines of code
        super().keyEvent()

class MyTable(KeyModifier,Table):
    pass

class MyButton(KeyModifier,Button):
    pass

But Pylance is angry because KeyModifier.super() doesn't have any keyEvent() method (which is true).

Is there a way to do it better? Also, I would like Pylance to warn me when using the KeyModifier with something not inherited from Widget.

This example comes from a PyQT app, but the question is more general.

Edit:
Making KeyModifier a subclasss of Widget makes KeyModifier.super().keyEvent() call Widget.keyEvent() and I want to call the child class method (Table.keyEvent() or Button.keyEvent())

答案1

得分: 1

这有帮助吗？

from abc import abstractmethod


class Table:
    pass


class Button:
    pass


class KeyModifier:
    @abstractmethod
    def custom_operation(self):
        pass

    def key_event(self, condition):
        if condition:
            self.custom_operation()


class MyTable(KeyModifier, Table):
    def __init__(self):
        super(MyTable, self).__init__()

    def custom_operation(self):
        pass


class MyButton(KeyModifier, Button):
    def custom_operation(self):
        pass

答案2

得分: 0

如果你让KeyModifier继承自Widget，警告将会消失，因为keyEvent将会为该对象实际定义。如果你还在修改后的类中添加super().keyEvent()调用，所有合适的事件将会触发，这要归功于一种叫做MRO（Method Resolution Order）的东西。

class Base:
    def event(self):
        print("Base")

class A(Base):
    def event(self):
        print("A")

class B(Base):
    def event(self):
        print("B")

class Modifier(Base):
    def event(self):
        print("Modified")
        super().event()

class ModifiedA(Modifier, A):
    def event(self):
        print("ModifiedA")
        super().event()

class ModifiedB(Modifier, B):
    def event(self):
        print("ModifiedB")
        super().event()

ModifiedA().event()

输出结果：

ModifiedA
Modified
A

需要注意的是，如果A和B不在它们自己的event方法中调用super（我相当肯定PyQt小部件会调用它们的父类方法），那么Modifier必须是第一个继承的类，因为这将导致它在MRO中首先出现，从而有机会调用其他类的方法。

class Base:
    def event(self):
        print("Base")

class A(Base):
    def event(self):
        print("A")

class B(Base):
    def event(self):
        print("B")

class Modifier(Base):
    def event(self):
        print("Modified")
        super().event()

class ModifiedA(Modifier, A):
    def event(self):
        print("ModifiedA")
        super().event()

class ModifiedB(Modifier, B):
    def event(self):
        print("ModifiedB")
        super().event()

ModifiedA().event()

ModifiedA
Modified
A

答案3

得分: 0

I've found a workaround as I don't really have to manage any class methods but the event that is being handled.

def KeyModifier(event: Event) -> Event:
    # some lines of code and edit 'event' if necessary
    return event

class MyButton(Button):
    def keyEvent(self, event: Event):
        super().keyEvent(KeyModifier(event))

我找到了一个解决方法，因为我实际上不需要管理任何类方法，只需要处理事件。

def KeyModifier(event: Event) -> Event:
    # 一些代码行，根据需要编辑 'event'
    return event

class MyButton(Button):
    def keyEvent(self, event: Event):
        super().keyEvent(KeyModifier(event))

我认为这是最简单的编写方式。谢谢大家的建议

def KeyModifier(event: Event) -> Event:
    # some lines of code and edit 'event' if necessary
    return event

class MyButton(Button):
    def keyEvent(self, event: Event):
        super().keyEvent(KeyModifier(event))