抽象类

from abc import abstractmethod, ABCMeta

# 抽象类是不能实例化的类
class Talker(metaclass=ABCMeta):

    @abstractmethod                 # 标记为抽象方法，子类必须实现这方法
    def talk(self):
        pass


class Said(Talker):
    def talk(self):                        # 子类实现抽象类的方法
        print('talk something')

class Herring:
    pass
    # def talk(self):
    #     print('Herring')


said = Said()
said.talk()
print(isinstance(said, Talker))
h = Herring()
print(Talker.register(Herring))        # 注册使Herring成为Talker的对象
print(isinstance(h, Talker))
print(issubclass(Herring, Talker))
# h.talk()                             # 区别继承，这里就不能调用父类的方法，抽象类失去意义