python - 最大公共(public)父类(super class)

Question

是否有任何简单的方法来获取对象列表的“最大公共(public)父类(super class)”？例如，如果

class A(object): pass
class B(A): pass
class C(A): pass
class D(B, C): pass
class E(C): pass
class F(D, E): pass

和

b = B()
d = D()
e = E()

然后

gcs(b, e) is A
gcs(d, e) is C
gcs(e, e) is E

Answer 1

基于 Martijn 的想法，但考虑到时间复杂度在这里不会成为问题，使用更简单的方法(感谢@veedrac 的输入):

def gcs(*instances):
    classes = [type(x).mro() for x in instances]
    for x in classes[0]:
        if all(x in mro for mro in classes):
            return x

print gcs(b, e)
print gcs(d, e)
print gcs(e, e)

输出:

<class '__main__.A'>
<class '__main__.C'>
<class '__main__.E'>

上述代码使用集合的轻微变体:

def gcs(*instances):
    mros = (type(ins).mro() for ins in instances)
    mro = next(mros)
    common = set(mro).intersection(*mros)
    return next((x for x in mro if x in common), None)