On 02/08/12 01:10, Hugo Arts wrote:
* small caveat: I'm entirely unsure of this, but I *think* if you create
CarModel with a metaclass that overrides __call__ you can change the way
__new__ and __init__ work? If anyone can confirm this, be my guest.
Correct. Metaclasses can essentially change *nearly* everything about how
classes and instances are created.
py> class MyMeta(type):
... def __call__(self, *args):
... instance = self.__new__(self, "magic")
... instance.__init__("happens")
... instance.colour = "sparkly"
... return instance
...
py>
py> class MyClass(object, metaclass=MyMeta):
... def __new__(cls, arg):
... print("received argument", arg)
... return super().__new__(cls, arg)
... def __init__(self, arg):
... print("received argument", arg)
... self.arg = arg
...
py>
py> inst = MyClass("these", "args", "are", "ignored")
received argument magic
received argument happens
py> inst.colour
'sparkly'
--
Steven
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