这种写法可以说就不是多态了，这特么的是变态啊。

# -*- coding: utf-8 -*-


class Animal(object):

    def speak(self):
        print("Hello, I'm is Animal.")


class Dog(Animal):

    def speak(self):
        print("Hello, I'm is Puppy.")


class Cat(Animal):

    def speak(self):
        print("Hello, I'm is Cat.")


class Botany(object):

    def speak(self):
        print("Hello, I'm is Botany, HaHaHa.")


def start_perform(animal):
    animal.speak()
    # if isinstance(animal, Animal):
    #     animal.speak()
    # else:
    #     raise TypeError("You're not a fucking animal!!!")


start_perform(Botany())

打印结果：

Hello, I'm is Botany, HaHaHa.