python中對單例模式的理解

標籤：span   self   process   python   執行個體   理解   proc   foo   style   

class Foo(object):    instance = None    def __init__(self):        pass    def process(self):        return ‘1234565‘    @classmethod   #版本1單例模式    def get_instance(cls):        if  Foo.instance:            return Foo.instance        else:            Foo.instance = Foo()            return Foo.instanceobj1 = Foo()print(obj1.process())obj2 = Foo()print(obj2.process())obj1不相等obj2  id(obj1)obj1 = Foo.get_instance()obj2 = Foo.get_instance()此時的obj1=obj2class Foo(object):    instance = None    def __init__(self):        self.name = ‘alex‘    def __new__(cls, *args, **kwargs):        if Foo.instance:            return Foo.instance        else:            obj = object.__new__(cls, *args, **kwargs) #建立對象的本質是new  new先執行            return return objobj1 = Foo()obj2 = Foo()print(id(obj1), id(obj2))  obj1=obj2  單例模式2 進階版  永遠用一個對象的執行個體！建立的對象內部封裝的值是一樣的 就搞成單例模式

 

python中對單例模式的理解