Python Implementation Singleton mode

Python Implementation Singleton mode

#  using Python to implement a singleton pattern #  method:  using the __new__ method Class singleton (object):     def  __new__ (Cls, *args, **kwargs):         if not  hasattr (cls,  ' _instance '):             cls._instance = object.__new__ (Cls, *args, **kwargs)          return cls._instanceclass testclass (SingleTon):     a = 1#   Method Two:  using adorners (decorator) def singleton1 (Cls, *args, **kwargs):     Instances = {}    def _singleton ():         if cls not in instances:             instances[cls] = cls (*args, **kwargs)          return  instAnces[cls]    return _singleton@singleton1class testclass1 (object):     a = 1#  Shared Properties    properties are shared, but not singleton mode Class singleton3 (object):     _state = {}    def __new__ (Cls, *args, **kwargs):         obj = object.__new__ (Cls, *args, **kwargs)         obj.__dict__ = cls._state         RETURN OBJCLASS TESTCLASS3 (SingleTon3):     a =  1TEST1 = TESTCLASS3 () TEST2 = TESTCLASS3 () test1.a = 2print (test1.a) print ( test2.a) print (test1) print (test2)

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Python Implementation Singleton mode