Question

我正在尝试创建一个抽象基类，它也继承了一个任意的 PySide6 类。但是，以下会产生错误 TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases。

from abc import ABC, abstractmethod

from PySide6.QtWidgets import QApplication, QWidget


class MyBaseWidget(QWidget, ABC):

    def __init__(self, parent=None):
        super().__init__(parent=parent)
    
    @abstractmethod
    def foo(self):
        pass


class MyConcreteWidget(MyBaseWidget):

    def __init__(self, parent=None):
        super().__init__(parent=parent)


app = QApplication([])
widget = MyConcreteWidget()
widget.show()
app.exec_()

我尝试使用以下解决方案解决此问题（灵感来自 Resolving metaclass conflicts、http://www.phyast.pitt.edu/~micheles/python/metatype.html、Multiple inheritance metaclass conflict 等）。

class MyMeta(ABCMeta, type(QWidget)): pass


class MyBaseWidget(QWidget, metaclass=MyMeta):

    def __init__(self, parent=None):
        super().__init__(parent=parent)
    
    @abstractmethod
    def foo(self):
        pass


class MyConcreteWidget(MyBaseWidget):

    def __init__(self, parent=None):
        super().__init__(parent=parent)


app = QApplication([])
widget = MyConcreteWidget()
widget.show()
app.exec_()

这在执行时没有错误，但在实例化 TypeError: Can't instantiate abstract class MyConcreteWidget with abstract methods foo 时我预计会出现类似 MyConcreteWidget 的错误。无法强制执行基类的接口确实会失去拥有抽象基类的好处。有什么解决办法吗？

尝试创建同时继承 PySide6 类的 Python 抽象类时的元类冲突

0 个答案: