python版本的责任链模式-优快云博客

本文介绍了一种使用Python实现的责任链模式。通过定义一系列处理对象并为这些对象提供一种链接方式来形成一条链，使得请求可以沿着这条链传递，直到被某个处理对象处理。具体实现了三个具体的处理者类，每个类负责处理特定范围内的请求，并将不属于自己处理范围的请求传递给下一个处理者。

# -*- coding:UTF-8 -*-
import abc


class Handler(metaclass=abc.ABCMeta):
    def __init__(self):
        self._successor = None

    def set_successor(self, successor):
        self._successor = successor

    @abc.abstractmethod
    def handle_request(self, request):
        pass


class ConcreteHandler1(Handler):
    def handle_request(self, request):
        if request >= 0 and request < 10:
            print("{}处理请求{}".format(self.__class__.__name__, request))
        elif self._successor != None:
            self._successor.handle_request(request)


class ConcreteHandler2(Handler):
    def handle_request(self, request):
        if request >= 10 and request < 20:
            print("{}处理请求{}".format(self.__class__.__name__, request))
        elif self._successor is not None:
            self._successor.handle_request(request)


class ConcreteHandler3(Handler):
    def handle_request(self, request):
        if request >= 20 and request < 30:
            print("{}处理请求{}".format(self.__class__.__name__, request))
        elif self._successor is not None:
            self._successor.handle_request(request)


if __name__ == "__main__":
    h1 = ConcreteHandler1()
    h2 = ConcreteHandler2()
    h3 = ConcreteHandler3()

    h1.set_successor(h2)
    h2.set_successor(h3)

    requests = [2, 5, 14, 22, 18, 3, 27, 20]
    for request in requests:
        h1.handle_request(request)