using metaclass __call__ to replace class instance

Ksenia Marasanova ksenia.marasanova at gmail.com
Fri Sep 9 14:21:29 CEST 2005


2005/9/9, Ksenia Marasanova <ksenia.marasanova at gmail.com>:
> class BasemethodMeta(type):
>     def __new__(cls, class_name, bases, new_attrs):
>         cls = type.__new__(cls, class_name, bases, new_attrs)
>         new_attrs['__metaclass__'].cls = cls
>         return cls
> 
>     def __call__(self):
>         return self.cls.get_foo()
> 
> class Basemethod(object):
>     __metaclass__ = BasemethodMeta
>     def get_foo(cls):
>         return cls.foo
>     get_foo = classmethod(get_foo)
> 
> 
> But it doesn't work as I expected:
> 
> print Class.method1()
> "foo2"
> print Class.method2()
> "foo2"

As usual, it helps to write things down :)

I found an alternative way, probably a lot easier to maintain: return
*instance* of Basemethod class in __new__ method of the
BasemethodMeta, and then use __call__ method of Basemethod class for
all the things.

Python is such fun...  

-- 
Ksenia



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