设计模式之python版(二)--策略模式

时间:2022-05-01 22:02:10

策略模式:

应用特性:接收任意对象,然后对不同的对象去做相同的一件事情。

结构特性:策略模式其实是利用了多态的特性,使用固定的方法,但是把对象作为个体抽离出来了,对象在这里有点象抽离出来的配置文件的意思

UML:


#!/usr/bin/env python
#encoding: utf-8

class baseclass:
def __init__(self):
pass

def dosomething(self):
pass

class newclass1(baseclass):
def __init__(self):
pass

def dosomething(self, perfix):
print perfix + ':dosomething1'

class newclass2(baseclass):
def __init__(self):
pass

def dosomething(self, perfix):
print perfix + ':dosomething2'

class newclass3(baseclass):
def __init__(self):
pass

def dosomething(self, perfix):
print perfix + ':dosomething3'


class setclass:
def __init__(self,something):
if 'newclass1' == something:
self.classobj = newclass1()
elif 'newclass2' == something:
self.classobj = newclass2()
elif 'newclass3' == something:
self.classobj = newclass3()
else:
return None

def dosomething(self,perfix):
self.classobj.dosomething(perfix)


if '__main__' == __name__:
class1 = setclass('newclass1')
class2 = setclass('newclass2')
class3 = setclass('newclass3')
print class1.__class__
print class2.__class__
print class3.__class__
class1.dosomething('class1')
class2.dosomething('class2')
class3.dosomething('class3')

结果:

__main__.setclass
__main__.setclass
__main__.setclass
class1:dosomething1
class2:dosomething2
class3:dosomething3