Spread array as dictionary key

Asked Oct 09 '18 at 07:54

Active Oct 09 '18 at 10:25

Viewed 344 times

Consider the following dict:

{
    "a" : {
        "b" : [
            entry,
            entry,
            ...
        ]
    }
}

Is there any way to address each entry given a key in the form "a.b"?
Ideally one could write something like dict[*("a.b".split("."))] and get dict["a"]["b"], but I have found no way to do it in Python yet.

Edit 2

Since no one seems to really care about quality code, I ended up using a plain old for loop:

data = { "a" : { "b" : "foo" } }
key = "a.b"

d = data
for k in key.split("."):
    d = d[k]

d == data["a"]["b"] # True

Edit 3

Comments contain a valid solution:

import operator
from functools import reduce  # forward compatibility for Python 3

data = { "a" : { "b" : "foo" } }
key = "a.b"

d = reduce(operator.getitem, key.split("."), data)

d == data["a"]["b"] # True

However, apart from this, I guess there is no way to exploit some language feature to do that, which kind of was the original question.

edited Oct 09 '18 at 10:25

asked Oct 09 '18 at 07:54

Samuele Pilleri

*Now* it's the correct duplicate. – deceze Oct 09 '18 at 09:00
@deceze No, it is not, it's a dict, not a class. In fact, it fails with error `AttributeError: 'dict' object has no attribute 'a'`. I will dive into `operator` to see if it has something for dictionaries. – Samuele Pilleri Oct 09 '18 at 09:36
Hmm, yeah, something about this question is bad luck. ***NOW*** it's the correct duplicate. – deceze Oct 09 '18 at 09:39
@deceze **NOW** we are talking, thanks for pointing it out. For the records, it's `reduce(operator.getitem, key.split("."), data)`. I think this would deserve an answer. – Samuele Pilleri Oct 09 '18 at 09:46
It already *has* an answer. In the duplicate. – deceze Oct 09 '18 at 09:47
At least remove the two wrong ones, they are misleading. Many thanks, today I learned something. – Samuele Pilleri Oct 09 '18 at 09:52

Spread array as dictionary key

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