Boris Borcic wrote:
> Arnaud Delobelle wrote:
>> macm<moura.ma...@gmail.com> writes:
>>
>>> Hi Folks
>>>
>>> How convert list to nested dictionary?
>>>
>>>>>> l
>>> ['k1', 'k2', 'k3', 'k4', 'k5']
>>>>>> result
>>> {'k1': {'k2': {'k3': {'k4': {'k5': {}}}}}}
>>>
>>> Regards
>>>
>>> macm
>>
>> reduce(lambda x,y: {y:x}, reversed(l), {})
>>
>
> d={}
> while L : d={L.pop():d}
Iterating over the keys in normal order:
>>> keys = "abcde"
>>> d = outer = {}
>>> for key in keys:
... outer[key] = inner = {}
... outer = inner
...
>>> d
{'a': {'b': {'c': {'d': {'e': {}}}}}}
The "functional" variant:
>>> d = {}
>>> reduce(lambda outer, key: outer.setdefault(key, {}), "abcde", d)
{}
>>> d
{'a': {'b': {'c': {'d': {'e': {}}}}}}
In a single expression if you are willing to pay the price:
>>> reduce(lambda (accu, outer), key: (accu, outer.setdefault(key, {})),
"abcde", ({},)*2)[0]
{'a': {'b': {'c': {'d': {'e': {}}}}}}
Peter
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