Python使用设计模式中的责任链模式与迭代器模式的示例
责任链模式
责任链模式：将能处理请求的对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理请求为止，避免请求的发送者和接收者之间的耦合关系。
#encoding=utf-8
#
#by panda
#职责连模式
def printInfo(info):
print unicode(info, 'utf-8').encode('gbk')
#抽象职责类
class Manager():
successor = None
name = ''
def __init__(self, name):
self.name = name
def SetSuccessor(self, successor):
self.successor = successor
def HandleRequest(self, request):
pass
#具体职责类：经理
class CommonManager(Manager):
def HandleRequest(self, request):
if request.RequestType == '请假' and request.Number <= 2:
printInfo('%s:%s 数量%d 被批准' % (self.name, request.RequestContent, request.Number))
else:
if self.successor != None:
self.successor.HandleRequest(request)
#具体职责类：总监
class Majordomo(Manager):
def HandleRequest(self, request):
if request.RequestType == '请假' and request.Number <= 5:
printInfo('%s:%s 数量%d 被批准' % (self.name, request.RequestContent, request.Number))
else:
if self.successor != None:
self.successor.HandleRequest(request)
#具体职责类：总经理
class GeneralManager(Manager):
def HandleRequest(self, request):
if request.RequestType == '请假':
printInfo('%s:%s 数量%d 被批准' % (self.name, request.RequestContent, request.Number))
elif request.RequestType == '加薪' and request.Number <= 500:
printInfo('%s:%s 数量%d 被批准' % (self.name, request.RequestContent, request.Number))
elif request.RequestType == '加薪' and request.Number > 500:
printInfo('%s:%s 数量%d 再说吧' % (self.name, request.RequestContent, request.Number))
class Request():
RequestType = ''
RequestContent = ''
Number = 0
def clientUI():
jinLi = CommonManager('金力')
zongJian = Majordomo('宗健')
zhongJingLi = GeneralManager('钟金利')
jinLi.SetSuccessor(zongJian)
zongJian.SetSuccessor(zhongJingLi)
request = Request()
request.RequestType = '请假'
request.RequestContent = '小菜请假'
request.Number = 1
jinLi.HandleRequest(request)
request.RequestType = '请假'
request.RequestContent = '小菜请假'
request.Number = 5
jinLi.HandleRequest(request)
request.RequestType = '加薪'
request.RequestContent = '小菜要求加薪'
request.Number = 500
jinLi.HandleRequest(request)
request.RequestType = '加薪'
request.RequestContent = '小菜要求加薪'
request.Number = 1000
jinLi.HandleRequest(request)
return
if __name__ == '__main__':
clientUI();
类图：
迭代器模式
迭代器模式：提供一种方法顺序访问一个聚合对象中的各个元素，而又不暴露该对象的内部表示。
python内置支持这种模式，所以一般来说，不用自己写，
#encoding=utf-8
#
#by panda
#迭代器(Iterator)模式
def printInfo(info):
print unicode(info, 'utf-8').encode('gbk')
#迭代器抽象类
class Iterator:
def First(self):
pass
def Next(self):
pass
def IsDone(self):
pass
def CurrentItem(self):
pass
#集合抽象类
class Aggregate:
def CreateIterator(self):
pass
#具体迭代器类：
class ConcreteIterator(Iterator):
aggregate = None
current = 0
def __init__(self, aggregate):
self.aggregate = aggregate
self.current = 0
def First(self):
return self.aggregate[0]
def Next(self):
ret = None
self.current += 1
if(self.current < len(self.aggregate)):
ret = self.aggregate[self.current]
return ret
def IsDone(self):
if(self.current < len(self.aggregate)):
return False
else:
return True
def CurrentItem(self):
ret = None
if(self.current < len(self.aggregate)):
ret = self.aggregate[self.current]
return ret
#具体集合类
class ConcreteAggregate(Aggregate):
items = None
def __init__(self):
self.items = []
def clientUI():
a = ConcreteAggregate()
a.items.append('大鸟')
a.items.append('小菜')
a.items.append('行李')
a.items.append('老外')
a.items.append('公交内部员工')
a.items.append('小偷')
printInfo('---------迭代器模式-------------')
i = ConcreteIterator(a.items)
item = i.First()
while(False == i.IsDone()):
printInfo("%s 请买车票！" % i.CurrentItem());
i.Next()
printInfo('\n---------python内部迭代-------------')
for item in a.items:
printInfo("%s 请买车票！" % item);
return
if __name__ == '__main__':
clientUI();
类图：
