On Sat, Jan 17, 2015 at 4:49 AM, Tim <[email protected]> wrote:
> I want to get a union of all the values that any 'things' key may have, even
> in a nested dictionary (and I do not know beforehand how deep the nesting
> might go):
>
> d = {'things':1, 'two':{'things':2}}
>
> def walk(obj, res):
> if not hasattr(obj, 'keys'):
> return set(), set()
>
> if 'things' in obj:
> res.add(obj['things'])
>
> for k in obj:
> walk(obj[k], res)
>
> return res
>
> walk(d, set()) # returns {1, 2}
>
> Is it better to use a global to keep track of the values or does it even
> matter?
I would use a parameter rather than a global, but I'd make the
parameter optional:
def all_keys(obj, accum=None):
if accum is None: accum=set()
if 'things' in obj:
res.add(obj['things'])
for val in obj.values():
all_keys(val, accum)
return all_keys
ChrisA
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