Re: Using dict as object

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From	Oscar Benjamin <oscar.j.benjamin@gmail.com>
Subject	Re: Using dict as object
Date	Wed, 19 Sep 2012 23:04:26 +0000 (UTC)
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On 2012-09-19, Pierre Tardy <tardyp@gmail.com> wrote:
> --===============1362296571==
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>>
>>  This has been proposed and discussed and even implemented many
>> times on this list and others.
>>
> I can find this question on SO
> http://stackoverflow.com/questions/4984647/accessing-dict-keys-like-an-attribute-in-python
> which is basically answered with this solution
>
> class AttributeDict(dict):
>     __getattr__ = dict.__getitem__
>     __setattr__ = dict.__setitem__
>
>
> but this does not allow recursive access, you would need to first convert
> all nested dictionaries to AttributeDict.
> a.b.c.d = 2 # fail
> a.b = dict(c=3)
> a.b.c=4 # fail

There is no way to control "recursive access" in Python. The statement

a.b.c = 2

is equivalent to the statements

o = a.b   # o = a.__getattr__('b')
o.c = 2   # o.__setattr__('c', 2)

The way that the o.c assignment is handled is determined by the type of o
regardless of the type of a. If you're looking for a way to change only the
type of a and make a custom __(set|get)attr__ work for all dicts that are
indirectly referred to then there is no solution to your problem.

Oscar

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Using dict as object Pierre Tardy <tardyp@gmail.com> - 2012-09-19 03:24 -0700
  Re: Using dict as object Dave Angel <d@davea.name> - 2012-09-19 07:45 -0400
  Re: Using dict as object Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2012-09-19 15:02 +0200
  Re: Using dict as object Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-19 14:04 +0000
  Re: Using dict as object Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-19 23:04 +0000

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