对类方法进行约束（类的抽象方法ABC+raise抛出异常 ）

#base.py
#####方法一######
from abc import ABCMeta
from abc import abstractmethod

class BaseMessage(metaclass=ABCMeta):

    @abstractmethod
    def send(self,subject,body,to,name):
        pass

########方法二#######
class BaseMessage(object):
    def send(self, subject, body, to, name):
        raise NotImplementedError('未实现send方法')

#######dingding.py#########
from .base import BaseMessage

class DingDing(BaseMessage):
    def __init__(self):
        pass

    def send(self,subject,body,to,name):
        print('钉钉消息发送成功')