07.01.2011, 23:48, "Fuzzyman" <fuzzy...@gmail.com>:
> On Jan 7, 3:18 pm, kost BebiX <k...@ya.ru>; wrote:
>
>> 07.01.2011, 17:14, "Jean-Michel Pichavant" <jeanmic...@sequans.com>;:
>>> kost BebiX wrote:
>>>> šSorry for top posting, didn't know about that) I'm quote new to posting
>>>> to mailing lists.
>>>> šWell, actually the code you showed doesn't work)
>>>>>>> šclass A(object):
>>>> š.. ššššdef __init__(self):
>>>> š.. ššššššššself.d = {}
>>>> š.. ššššdef __getattr__(self, key):
>>>> š.. šššššššštry:
>>>> š.. ššššššššššššreturn self.d[key]
>>>> š.. ššššššššexcept KeyError:
>>>> š.. ššššššššššššraise AttributeError
>>>>>>> šfrom copy import deepcopy
>>>>>>> ša = A()
>>>>>>> šdeepcopy(a)
>>>> šException RuntimeError: 'maximum recursion depth exceeded while calling
>>>> a Python object' in <type 'exceptions.AttributeError'> ignored
>>>> šException RuntimeError: 'maximum recursion depth exceeded while calling
>>>> a Python object' in <type 'exceptions.AttributeError'> ignored
>>>> š0: <__main__.A object at 0xda0250>
>>> It does work as I pasted it with python2.5.
>>> recursion problems often occur when overriding __getattr__ or
>>> __getattribute__ *AND* accessing self attributes using self.attr form
>>> inside the method.
>>> try to change
>>> ššššreturn self.d[key]
>>> into
>>> ššššreturn object.__getattribute__(self, 'd')[key]
>>> Just speculating though, I cannot test since I don't reproduce the problem.
>>> JM
>> Yeap, that works. So, is it a python 2.6 bug? Because documentation says
>> that __getattr__ is called only after property was not found (and
>> __getattr__ was actually invented in a way that you can use self inside it).
>
> That is true (that __getattr__ is called only if the attribute doesn't
> exist), however deepcopy works by creating a new instance *without*
> calling __init__. When it is copying the attributes self.d *doesn't*
> exist initially. You should work around this case in your __getattr__
> if you want your object to be deep-copyable.
>
> Michael Foord
> --
> http://www.voidspace.org.uk/
Yeah, but, I mean, shouldn't deepcopy copy the attributes before it gets to
calling __getattr__?
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