方法一
Python代码
import threading class Singleton(object): __instance = None __lock = threading.Lock() # used to synchronize code def __init__(self): "disable the __init__ method" @staticmethod def getInstance(): if not Singleton.__instance: Singleton.__lock.acquire() if not Singleton.__instance: Singleton.__instance = object.__new__(Singleton) object.__init__(Singleton.__instance) Singleton.__lock.release() return Singleton.__instance
1.禁用__init__方法，不能直接创建对象。
2.__instance，单例对象私有化。
3.@staticmethod，静态方法，通过类名直接调用。
4.__lock，代码锁。
5.继承object类，通过调用object的__new__方法创建单例对象，然后调用object的__init__方法完整初始化。
6.双重检查加锁，既可实现线程安全，又使性能不受很大影响。
方法二：使用decorator
Python代码
#encoding=utf-8 def singleton(cls): instances = {} def getInstance(): if cls not in instances: instances[cls] = cls() return instances[cls] return getInstance @singleton class SingletonClass: pass if __name__ == '__main__': s = SingletonClass() s2 = SingletonClass() PRint s print s2
也应该加上线程安全
附：性能没有方法一高
Python代码
import threading class Sing(object): def __init__(): "disable the __init__ method" __inst = None # make it so-called private __lock = threading.Lock() # used to synchronize code @staticmethod def getInst(): Sing.__lock.acquire() if not Sing.__inst: Sing.__inst = object.__new__(Sing) object.__init__(Sing.__inst) Sing.__lock.release() return Sing.__inst