folks, what's wrong with this?

Robert Kern robert.kern at
Thu Apr 1 15:10:51 EDT 2010

On 2010-04-01 13:56 PM, Ani wrote:
> Hi All:
> I am just a beginner in python. Can anyone please tell me what is
> wrong with this piece of code?
> import copy
> class BaseDummyObject(object):
>      def __init__(self):
>          pass
>      def __getattr__(self, item):
>          try:
>              return self.__dict__.__getitem__(item)
>          except KeyError:
>              print "Attribute Error: attr %s of class %s non-existent!"
> %(item,
> self.__class__.__name__)

You need to raise an AttributeError here. Otherwise, it implicitly returns None 
for all attributes not in the __dict__ and thus confusing the copy.deepcopy() code.

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco

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