class Singleton (object):
    def __new__(cls, *args, **kwds):
 
        # Tenta pegar a instância existente:
        it = cls.__dict__.get("__it__")
 
        # Se exitir, retorne-a:
        if it is not None:
            return it
 
        # Se não, crie uma instância nova:
        cls.__it__ = it = object.__new__(cls)
 
        # Inicializa a instância:
        it.init(*args, **kwds)
 
        # Retorna a nova instância:
        return it
 
    def init(self, *args, **kwds):
        print("Objeto inicializado")
 
obj1 = Singleton()
obj1.name = "Foo Bar"
 
obj2 = Singleton()
print(obj2.name)

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