在Mixin中调用超类的设置器 [英] Calling the setter of a super class in a mixin

问题描述

假设我有以下(在生物学上不是很正确)的类:

Suppose I have the following (not quite biologically correct) classes:

class AnimalBaseClass:
    def __init__(self):
        self._limbs = None

    @property
    def limbs(self):
        return self._limbs

    @limbs.setter
    def limbs(self, value):
        self.paws = value
        self._limbs = value


class BipedalMixIn:
    @property
    def limbs(self):
        return super().limbs

    @limbs.setter
    def limbs(self, value):
        self.bipedal = (value == 2)
        # does not work
        super().limbs = value

此处super().limbs = value是 Python不支持的.如果BipedalMixIn不是mixin，我可以直接使用超类的名称，但是有什么简单的选择可以在mixin中调用超类的setter?

Here super().limbs = value is not supported by python. If BipedalMixIn was not a mixin, I could use the super class's name directly, but is there any simple alternative, to call the super class's setter in a mixin?

推荐答案

尽管可以使用任何更简单的答案，但仍可以进行以下工作.

The following works, although any simpler answers are appreciated.

class AnimalBaseClass:
    def __init__(self):
        self._limbs = None

    @property
    def limbs(self):
        return self._limbs

    @limbs.setter
    def limbs(self, value):
        self.paws = value
        self._limbs = value


class BipedalMixIn:
    @property
    def limbs(self):
        return super().limbs

    @limbs.setter
    def limbs(self, value):
        self.bipedal = (value == 2)
        # works!
        super(BipedalMixIn, self.__class__).limbs.__set__(self, value)


class Bird(BipedalMixIn, AnimalBaseClass):
    pass


bird = Bird()
bird.limbs = 2
print(bird.bipedal)    # True
print(bird.paws)        # 2

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