defaultdict of arbitrary depth

Steve Holden steve at holdenweb.com
Fri Aug 17 07:40:35 CEST 2007


Paul McGuire wrote:
> On Aug 16, 11:19 pm, Carsten Haese <cars... at uniqsys.com> wrote:
>> On Thu, 2007-08-16 at 20:25 -0700, Paul McGuire wrote:
>>> [...]
>>> I've hacked out this recursivedefaultdict which is a
>>> defaultdict(defaultdict(defaultdict(...))), arbitrarily deep depending
>>> on the keys provided in the reference.
>>> Please comment.
>>> [...]
>>> class recursivedefaultdict(object):
>>>     def __init__(self):
>>>         self.__dd = defaultdict(recursivedefaultdict)
>>>     def __getattr__(self,attr):
>>>         return self.__dd.__getattribute__(attr)
>>>     def __getitem__(self,*args):
>>>         return self.__dd.__getitem__(*args)
>>>     def __setitem__(self,*args):
>>>         return self.__dd.__setitem__(*args)
>> This is shorter:
>>
>> from collections import defaultdict
>>
>> class recursivedefaultdict(defaultdict):
>>     def __init__(self):
>>         self.default_factory = type(self)
>>
>> --
>> Carsten Haesehttp://informixdb.sourceforge.net- Hide quoted text -
>>
>> - Show quoted text -
> 
> Of course, very short and sweet!  Any special reason you wrote:
>         self.default_factory = type(self)
> instead of:
>         self.default_factory = recursivedefaultdict
> ?
It's more robust under subclassing.

regards
  Steve
-- 
Steve Holden        +1 571 484 6266   +1 800 494 3119
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