实例解析Python设计模式编程之桥接模式的运用
这篇文章主要介绍了Python设计模式编程之桥接模式的运用,桥接模式主张把抽象部分与它的实现部分分离,需要的朋友可以参考下
我们先来看一个例子：
#encoding=utf-8
#
#by panda
#桥接模式
def printInfo(info):
print unicode(info,
'utf-8').encode('gbk')
#抽象类：手机品牌
class HandsetBrand():
soft = None
def SetHandsetSoft(self,
soft):
self.soft =
soft
def
Run(self):
pass
#具体抽象类：手机品牌1
class HandsetBrand1(HandsetBrand):
def
Run(self):
printInfo('手机品牌1:')
self.soft.Run()
#具体抽象类：手机品牌2
class HandsetBrand2(HandsetBrand):
def
Run(self):
printInfo('手机品牌2:')
self.soft.Run()
#功能类：手机软件
class HandsetSoft():
def
Run(self):
pass
#具体功能类：游戏
class HandsetGame(HandsetSoft):
def
Run(self):
printInfo('运行手机游戏')
#具体功能类：通讯录
class HandsetAddressList(HandsetSoft):
def
Run(self):
printInfo('运行手机通信录')
def clientUI():
h1 =
HandsetBrand1()
h1.SetHandsetSoft(HandsetAddressList())
h1.Run()
h1.SetHandsetSoft(HandsetGame())
h1.Run()
h2 =
HandsetBrand2()
h2.SetHandsetSoft(HandsetAddressList())
h2.Run()
h2.SetHandsetSoft(HandsetGame())
h2.Run()
return
if __name__ == '__main__':
clientUI();
"""This class defines the
interface for implementation classes.
"""
def__init__(self, form="stay at
home"):
self.form=form
pass
defGetForm(self):
returnself.form
pass
pass
"""This class implements the
Implementor interface and defines its concrete
implementation.
"""
def__init__(self, form="by
group"):
super(Group,self).__init__(form)
pass
pass
"""This class implements the
Implementor interface and defines its concrete
implementation.
"""
def__init__(self, form="by
myself"):
super(Independent,self).__init__(form)
pass
"""This class (a) defines the
abstraction's interface, and (b) maintains a
reference to an object of type
Implementor.
"""
m_TravelForm=TravelForm()
def__init__(self, info):
self.info=info
pass
defGetInfo(self):
#
imp->Operation();
returnprint(self.info
" " self.form.GetForm())
pass
defSetForm(self, form):
self.form=form
pass
"""This class extends the
interface defined by Abstraction.
"""
def__init__(self, info="Go to
DaLian "):
super(DaLian,self).__init__(info)
pass
"""This class extends the
interface defined by Abstraction.
"""
def__init__(self, info="Go to
ShangHai"):
super(ShangHai,self).__init__(info)
pass
destination=ShangHai()
destination.SetForm(Group())
destination.GetInfo()
destination=DaLian()
destination.SetForm(Independent())
destination.GetInfo()
我们先来看一个例子：
#encoding=utf-8
#
#by panda
#桥接模式
def printInfo(info):
#抽象类：手机品牌
class HandsetBrand():
#具体抽象类：手机品牌1
class HandsetBrand1(HandsetBrand):
#具体抽象类：手机品牌2
class HandsetBrand2(HandsetBrand):
#功能类：手机软件
class HandsetSoft():
#具体功能类：游戏
class HandsetGame(HandsetSoft):
#具体功能类：通讯录
class HandsetAddressList(HandsetSoft):
def clientUI():
if __name__ == '__main__':
可以总结出类图是这样的：
所以，桥接模式的概念在于将系统抽象部分与它的实现部分分离，使它们可以独立地变化。
由于目标系统存在多个角度的分类，每一种分类都会有多种变化，那么就可以把多角度分离出来，让它们独立变化，减少它们之间的耦合。
下面我们再来看一个实例：
基本原理请参考相关书籍，这里直接给实例
假期旅游 从目的地角度可以分为 上海和大连，从方式角度可以分为跟团和独体
桥接模式把这两种分类连接起来可以进行选择。
类图：
# -*- coding: utf-8
-*-
#######################################################
#
# tour.py
# Python implementation of
the Class DaLian
# Generated by Enterprise
Architect
# Created
on: 11-十二月-2012 16:53:52
#
#######################################################
from__future__importdivision
from__future__importprint_function
from__future__importunicode_literals
fromfuture_builtinsimport*
classTravelForm(object):
classGroup(TravelForm):
classIndependent(TravelForm):
classDestination(object):
classDaLian(Destination):
classShangHai(Destination):
#客户端
if(__name__=="__main__"):
运行结果