Concise idiom to initialize dictionaries

[Caleb Hattingh]

Steve,

Not only did you answer my silly question, but also the question I  
actually wanted to ask ...__getattribute__ is what I was thinking of.

thats cool :)
thx
Caleb

On Thu, 11 Nov 2004 20:30:18 +0000 (UTC), Steven Bethard  
<steven.bethard at gmail.com> wrote:

> Caleb Hattingh <caleb1 <at> telkomsa.net> writes:
>>
>> For interest sake, how would such a thing look with new-style classes?   
>> My
>> (likely misinformed) impression is that __getattr__ for example, doesn't
>> behave in quite the same way?
>
> Just the same[1] =)
>
>>>> class AllDicts(object):
> ...     def __getattr__(self, name):
> ...         d = {}
> ...         setattr(self, name, d)
> ...         return d
> ...     def __repr__(self):
> ...         items = self.__dict__.items()
> ...         items.sort()
> ...         return '\n'.join(['%s -> %r' % item for item in items])
> ...
>>>> ad = AllDicts()
>>>> ad.a[1] = 99
>>>> ad.b[2] = 42
>>>> ad.b[3] = 11
>>>> ad
> a -> {1: 99}
> b -> {2: 42, 3: 11}
>>>>
>
> I believe that __getattr__ works just the same (but to check for  
> yourself, see
> http://docs.python.org/ref/attribute-access.html).  I think what you're  
> thinking
> of is __getattribute__ which new-style classes offer *in addition* to
> __getattr__.  While __getattr__ is called only if an attribute is not  
> found,
> __getattribute__ is called unconditionally for every attribute access.
>
> Steve
>
> [1] modulo my preference for list comprehensions/generator expressions  
> instead
> of map
>