overloading __getattr__ and inheriting from dict

Robert Brewer fumanchu at amor.org
Fri Mar 12 20:05:55 CET 2004


Benoît Dejean wrote:
> class TargetWrapper(dict):
> 
>     def __init__(self, **kwargs):
>         dict.__init__(self, kwargs)
> 
>     __getattr__ = dict.__getitem__
>     __setattr__ = dict.__setitem__
>     __delattr__ = dict.__delitem__
> 
> then 
> 
> tw = TargetWrapper()
> tw.a = "spam" # ok
> del tw.a # ok
> tw.b = "egg"
> print tw.b
> 
> last line give me an
> AttributeError: 'TargetWrapper' object has no attribute 'b'
> 
> if i define
> 
>     def __getitem__(self, name):
>         return dict.__getitem__(self, name)
> 
>     __getattr__ = __getitem__
> 
> then the accessing the b attribute is ok. what's wrong ?

Not sure (analysis is too much for my tiny brain right now), but why don't you try:

    def __getattr__(self, name):
        return self[name]

That's the "usual" way to override __getattr__.

FuManChu




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