On Tue, 8 Aug 2006 01:33:31 +0200 "Andre Meyer" <[EMAIL PROTECTED]> wrote:
> > Am I missing something here? What is the preferred pythonic way of > implementing singleton elegantly? I think the most "elegant" is with a metaclass, since I feel like a singleton is not just an ordinary type (and __init__ must be called only once)... but, as "practicality beats purity", the most pythonic way is probably using the __new__ method and inheritance. Something like this: >>> class Singleton(object): ... def __new__(cls, *args, **kwds): ... try: ... return cls._it ... except AttributeError: ... cls._it = object.__new__(cls, *args, **kwds) ... return cls._it ... >>> class A(Singleton): ... pass ... >>> x = A() >>> y = A() >>> x is y True But __init__ will be called once for each time you call A, even if it's always the same instance returned. If this is a problem, you'll need another method to use for initialization and call it only once. -- Pedro Werneck -- http://mail.python.org/mailman/listinfo/python-list
