class A:
pass
class B(A):
pass
class C(A):
pass
class D(B, C):
pass
class E:
pass
class F(D, E):
pass
class G(F, D):
pass
class I:
pass
class J(B, C):
pass
class K(A):
pass
class H(I, J, K):
pass
class Foo(H, G):
pass
原文：https://www.cnblogs.com/work14/p/10187575.html