How find all childrens values of a nested dictionary, fast!

macm moura.mario at gmail.com
Thu Nov 4 18:56:00 CET 2010


Hi Folks

Thanks a lot

Script from Diez works:

print list(f(a))

but should be

print list(f(a['a']['b']))

to fit my example.



About Peter script

I am receiving

>>> for v in f(a['a']['b']):
...     b.extend(v)
...
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
TypeError: 'int' object is not iterable

I am trying understand this error.

Best Regards and thanks a lot again!

Mario
macm






On 4 nov, 15:26, Peter Otten <__pete... at web.de> wrote:
> macm wrote:
> > How find all childrens values of a nested dictionary, fast!
>
> >>>> a = {'a' : {'b' :{'/' :[1,2,3,4], 'ba' :{'/' :[41,42,44]} ,'bc'
> >>>> :{'/':[51,52,54], 'bcd' :{'/':[68,69,66]}}},'c' :{'/' :[5,6,7,8]}},
> >>>> 'ab' : {'/' :[12,13,14,15]}, 'ac' :{'/' :[21,22,23]}} a['a']
> > {'c': {'/': [5, 6, 7, 8]}, 'b': {'ba': {'/': [41, 42, 44]}, '/': [1,
> > 2, 3, 4], 'bc': {'bcd': {'/': [68, 69, 66]}, '/': [51, 52, 54]}}}
> >>>> a['a']['b']
> > {'ba': {'/': [41, 42, 44]}, '/': [1, 2, 3, 4], 'bc': {'bcd': {'/':
> > [68, 69, 66]}, '/': [51, 52, 54]}}
> >>>> a['a']['b'].values()
> > [{'/': [41, 42, 44]}, [1, 2, 3, 4], {'bcd': {'/': [68, 69, 66]}, '/':
> > [51, 52, 54]}]
>
> > Now I want find all values of key "/"
>
> > Desire result is [41, 42, 44, 1, 2, 3, 4, 68, 69, 66, 51, 52, 54]
>
> > I am trying map, reduce, lambda.
>
> Hmm, I'm trying none of these and get a different result:
>
> >>> def f(d):
>
> ...     stack = [d.iteritems()]
> ...     while stack:
> ...             for k, v in stack[-1]:
> ...                     if k == "/":
> ...                             yield v
> ...                     else:
> ...                             stack.append(v.iteritems())
> ...                             break
> ...             else:
> ...                     stack.pop()
> ...>>> b = []
> >>> for v in f(a):
>
> ...     b.extend(v)
> ...>>> b
>
> [5, 6, 7, 8, 41, 42, 44, 1, 2, 3, 4, 68, 69, 66, 51, 52, 54, 21, 22, 23, 12,
> 13, 14, 15]
>
> What am I missing?
>
> Peter




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