07.01.2011, 16:22, "Jean-Michel Pichavant" <jeanmic...@sequans.com>:
> kost BebiX wrote:
>
>> You're absolutely right! Now try to do except Keyerror: raise
>> AttributeError and it will also fail. But why?
>>
>> 07.01.2011, 15:45, "Jean-Michel Pichavant" <jeanmic...@sequans.com>;:
>>> kost BebiX wrote:
>>>> Hi everyone!
>>>> I just saw a bug (?) in bson.dbref:DBRef.__getattr__
>>>>
>>>> Here's they're code:
>>>> def __getattr__(self, key):
>>>> return self.__kwargs[key]
>>>>
>>>> And when you do copy.deepcopy on that object it will raise you KeyError.
>>>> So here's a small piece of code that reproduces the problem:
>>> from http://docs.python.org/reference/datamodel.html
>>>
>>> About __getattr__
>>> "This method should return the (computed) attribute value or raise an
>>> AttributeError
>>> <http://docs.python.org/library/exceptions.html#exceptions.AttributeError>
>>> exception."
>>>
>>> The code you provided raises a KeyError thus methods such as 'getattr'
>>> will fail as they expect an AttributeError exception.
>>>
>>> JM
>>>
>>> --
>>> http://mail.python.org/mailman/listinfo/python-list
>
> please don't top post :)
>
> It fails because you simply did not returned any value (with your class
> A example).
>
> class A(object):
> def __init__(self):
> self.d = {}
> def __getattr__(self, key):
> try:
> *return* self.d[key]
> except KeyError:
> raise AttributeError
>
> works fine with deepcopy
>
> JM
>
> --
> http://mail.python.org/mailman/listinfo/python-list
Sorry for top posting, didn't know about that) I'm quote new to posting to
mailing lists.
Well, actually the code you showed doesn't work)
>>> class A(object):
.. def __init__(self):
.. self.d = {}
.. def __getattr__(self, key):
.. try:
.. return self.d[key]
.. except KeyError:
.. raise AttributeError
>>> from copy import deepcopy
>>> a = A()
>>> deepcopy(a)
Exception RuntimeError: 'maximum recursion depth exceeded while calling a
Python object' in <type 'exceptions.AttributeError'> ignored
Exception RuntimeError: 'maximum recursion depth exceeded while calling a
Python object' in <type 'exceptions.AttributeError'> ignored
0: <__main__.A object at 0xda0250>
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