背景
针对不同的操作系统版本，某个软件的安装操作有很大的区别，通过抽象工厂把多个版本的功能实现类分开了，现在需要提供给handler使用，属性比较多，太过繁琐，不适合用普通的代理方式．
代码
#!/usr/bin/env python
# -*- coding: utf-8 -*-
class Singleton(type):
"""通过类名设置单例模式
"""
_instances = {}
def __call__(cls, *args, **kwargs):
key = cls.__name__
if key not in cls._instances:
cls._instances[key] = super(Singleton, cls).__call__(*args, **kwargs)
if hasattr(cls._instances[key], "init_attr"):
cls._instances[key].init_attr()
return cls._instances[key]
class MyClass(object):
__metaclass__ = Singleton
def __init__(self):
self.running = 0
self.name = self.__class__.__name__
print "init: {}".format(self.name)
class MyClass1(MyClass):
def __init__(self):
super(MyClass1, self).__init__()
self.name = self.__class__.__name__
print "init: {}".format(self.name)
def test_method(self):
self.running = 1
print "test1: running: {}, name: {}".format(self.running, self.name)
@classmethod
def test_class(cls):
print "test1 class"
@staticmethod
def test_static():
print "test1 static"
class MyClass2(MyClass):
def __init__(self):
super(MyClass2, self).__init__()
self.name = self.__class__.__name__
print "init: {}".format(self.name)
def test_method(self):
self.running = 2
print "test2: running: {}, name: {}".format(self.running, self.name)
@classmethod
def test_class(cls):
print "test2 class"
@staticmethod
def test_static():
print "test2 static"
class MyClassType(type):
def __getattr__(self, item):
if self.get_version().startswith("6"):
func = getattr(self.class1, item)
else:
func = getattr(self.class2, item)
return func
class Manager(object):
__metaclass__ = MyClassType
class1 = MyClass1
class2 = MyClass2
VERSION = "6.7"
@classmethod
def get_version(cls):
"""查询版本
"""
return cls.VERSION
def __init__(self):
if self.get_version().startswith("6"):
self._manager = self.class1()
else:
self._manager = self.class2()
def __getattr__(self, item):
func = getattr(self._manager, item)
return func
def test():
manager1 = Manager()
Manager.VERSION = "6.7"
print manager1.running
manager1.test_method()
print manager1.running
Manager.test_class()
Manager.test_static()
Manager.VERSION = "7.4"
manager2 = Manager()
print manager2.running
manager2.test_method()
print manager2.running
Manager.test_class()
Manager.test_static()
manager3 = Manager()
print manager3.running
manager3.test_method()
print manager3.running
if __name__ == '__main__':
test()
