Python设计模式之职责链模式原理与用法实例分析

#!/usr/bin/env python
# -*- coding:utf-8 -*-
__author__ = 'Andy'
"""
大话设计模式
设计模式——职责链模式
职责链模式(Chain Of Responsibility):使多个对象都有机会处理请求，从而避免发送者和接收者的耦合关系。将对象连成链并沿着这条链传递请求直到被处理
(在调用时要定义好哪个实例是哪个实例的职责上一级)请求沿着定义的链条传递给可以处理请求的对象
"""
#抽象一个处理类
class Handle(object):
  def __init__(self):
    self.successor = ''
  def setsuccessor(self, successor):
    self.successor = successor
  def handle_request(self,request):
    pass
# 具体处理者类1
class ConcreteHandle1(Handle):
  def handle_request(self,request):
    if request>0 and request<=10:
      print "ConcreteHandle1处理请求 ",request
    else:
      self.successor.handle_request(request)
# 具体处理者类2
class ConcreteHandle2(Handle):
  def handle_request(self,request):
    if request>10 and request<=20:
      print "ConcreteHandle2处理请求 ",request
    else:
      self.successor.handle_request(request)
if __name__=="__main__":
  c1 = ConcreteHandle1()
  c2 = ConcreteHandle2()
  c1.setsuccessor(c2)
  for i in range(6,15,2):
    c1.handle_request(i)