class or instance method

Miles Kaufmann milesck at umich.edu
Sun Jun 21 23:56:01 CEST 2009


On Jun 21, 2009, at 5:23 PM, Scott David Daniels wrote:
> Hrvoje Niksic wrote:
>> ...
>> class class_or_instance(object):
>>    def __init__(self, fn):
>>        self.fn = fn
>>    def __get__(self, obj, cls):
>>        if obj is not None:
>>            return lambda *args, **kwds: self.fn(obj, *args, **kwds)
>>        else:
>>            return lambda *args, **kwds: self.fn(cls, *args, **kwds)
>> ...
>
> Just to polish a bit:
>
>    import functools
>
>    class ClassOrInstance(object):
>        def __init__(self, fn):
>            self._function = fn
>            self._wrapper = functools.wraps(fn)
>
>        def __get__(self, obj, cls):
>            return self._wrapper(functools.partial(self._function,
>                           cls if obj is None else obj))



from types import MethodType

class ClassOrInstance(object):
     def __init__(self, func):
         self._func = func

     def __get__(self, obj, cls):
         return MethodType(self._func, cls if obj is None else obj, cls)


-Miles




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