magical expanding hash

[Steve Holden]

Steven Bethard wrote:
> Paul Rubin wrote:
> 
>>Hmm,
>>
>>   x[a][b][c][d] = e    # x is a "magic" dict
>>
>>becomes
>>
>>   x.setdefault(a,{}).setdefault(b,{}).setdefault(c,{})[d] = e
>>
>>if I understand correctly.  Ugh.
> 
> 
> Agreed.  I really hope that Python 3.0 applies Raymond Hettinger's 
> suggestion "Improved default value logic for Dictionaries" from
>      http://wiki.python.org/moin/Python3%2e0Suggestions
> 
> This would allow you to make the setdefault() call only once, instead of 
> on every lookup:
> 
>      class meh(dict):
>          def __init__(self, *args, **kwargs):
>              super(meh, self).__init__(*args, **kwargs)
>              self.setdefault(function=meh)
> 
> STeVe
> 
In fact, why not go one better and also add a "default" keyword 
parameter to dict()?

regards
  Steve
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