Python中如何收集父类的所有叶子子类？

Question

给定一个名为

ParentClass

的基类，我如何找到它的所有叶子类？例如，如果我有：

class ParentClass:
    pass

class SubClass1(ParentClass):
    pass

class SubClass2(ParentClass):
    pass

class SubClass3(ParentClass):
    pass

class SubClass4(SubClass2):
    pass

class SubClass5(SubClass2):
    pass

class SubClass6(SubClass2, SubClass3):
    pass

我想要一个包含

[SubClass1, SubClass4, SubClass5, SubClass6]

的列表，而不是

SubClass2

或

SubClass3

，因为它们不是继承层次结构中的叶子。

Answer 1

此函数从父类开始，迭代其子类，将唯一的叶子类附加到列表中。

def leaf_subclasses(parent_class):
    leaves = []
    subclasses = [parent_class]
    while subclasses:
        next_subclasses = []
        for cls in subclasses:
            if cls.__subclasses__():
                next_subclasses.extend(cls.__subclasses__())
            elif cls not in leaves:
                leaves.append(cls)
        subclasses = next_subclasses
    return leaves

print(leaf_subclasses(ParentClass))