#encoding=utf-8
__author__ = ‘kevinlu1010@qq.com‘

class ADD():
    def getResult(self,*args):
        return args[0]+args[1]
class SUB():
    def getResult(self,*args):
        return  args[0]-args[1]
class MUL():
    def getResult(self,*args):
        return  args[0]*args[1]
class DIV():
    def getResult(self,*args):
        try:
            return  args[0]/args[1]
        except:return 0
class UNKnow():
    def getResult(self,op1,op2):
        return ‘unknow‘
class Factory():
    Classes={‘+‘:ADD,‘-‘:SUB,‘*‘:MUL,‘/‘:DIV}
    def getClass(self,key):
        return self.Classes[key]() if key in self.Classes else  UNKnow()

if __name__==‘__main__‘:
    key=‘+‘
    op1=91
    op2=45
    factory=Factory()
    c=factory.getClass(key)
    r=c.getResult(op1,op2)
    print r

#encoding=utf-8
__author__ = ‘kevinlu1010@qq.com‘

class Base():
    def getPrice(self,price):
        pass
class Origin(Base):
    def getPrice(self,price):
        return price
class Vip(Base):
    def getPrice(self,price):
        return price*0.8
class Sale(Base):
    def getPrice(self,price):
        return price-price/100*20
class Context():
    def __init__(self,c):
        self.c=c
    def getPrice(self,price):
        return self.c.getPrice(price)

if __name__==‘__main__‘:
    strategy={}
    strategy[0]=Context(Origin())
    strategy[1]=Context(Vip())
    strategy[2]=Context(Sale())
    price=485
    s=2
    price_last=strategy[s].getPrice(price)
    print price_last