Retrieving values in nested dict based on keys in a list

Question

data = {"c":{"files":"s","d":{"files":["nothing"]}}}
positions = ["c","d","files"]

How can I get to position I have in list "positions"? I need to get from list "positions" something like this:

data["c"]["d"]["files"]

I also need to work with list which is on that position. I already tried something, but I couldn't work with that list in way I would want to.

def goto(data,positions):
    temp = data
    for i in positions:
        temp = temp[i]

Is there any cool way to do it?

Answer 1

This is a job for reduce !

reduce(lambda a,b: a[b], positions, data)

If you're using Python 3, you'll need to import reduce like so:

from functools import reduce

In Python 2, it's a built-in function, and thus doesn't need importing.