Nested and flatten dictionary from JSON by using recursion

Question

I have the following .json file:

{
    "level1_one":"1",
    "level1_two":{
        "level2_one":"2",
        "level2_two":{
            "level3_one":"bottom"
        }
    }
}

I need to give it nested and flatten representation like so:

{
    "level1_two": {
        "level2_two": {
            "level3_one": "bottom"
        },
        "level2_one": "2"
    },
    "level1_one": "1"
}

and

{
    "level2_one": "2",
    "level3_one": "bottom",
    "level1_one": "1"
}

I know I can easily achieve the nested form by simply doing this:

def json_parser(filename):
    data = json.load(open(filename))
    print(data)

The problem is it needs to be done by using recursion for both cases. I tried almost everything I could find around here but without much success. How I can do this?

Almost everything I could find by searching recursion. The problem is once getting to the bottom of the json I can't find a way to represent it back. It needs to be done this way as it's kind of challenge. I have some experience with JSON but this is coming a bit wired. — sretko
– sretko, Commented Dec 5, 2017 at 17:02
thanks to @Ajax1234 the flatten pattern is done. About the nested I already know how to do it without it but it needs to be done by using recursion. — sretko
– sretko, Commented Dec 5, 2017 at 17:41

Ajax1234 · Accepted Answer · 2017-12-05 17:04:07Z

1

You can try this:

s = {
"level1_one":"1",
"level1_two":{
    "level2_one":"2",
    "level2_two":{
        "level3_one":"bottom"
    }
  }
}
def flatten(s):   
   for i in s:
      if not isinstance(s[i], dict):
          yield (i, s[i])
      else:
           for b in flatten(s[i]):
              yield b

new_data = dict(list(flatten(s)))

Output:

{'level2_one': '2', 'level3_one': 'bottom', 'level1_one': '1'}

answered Dec 5, 2017 at 17:04

Ajax1234

71.7k9 gold badges67 silver badges110 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

sretko Over a year ago

Great. As expected. Can you suggest something for the nested version.

Ajax1234 Over a year ago

@sretko glad to help! Regarding the nested version, I do not seen any difference between your desired nested version and the original data structure? Could you clarify this?

sretko Over a year ago

It's just edited. Take another look and you are going to see it clearly.

RoachLord · Accepted Answer · 2017-12-05 17:02:55Z

0

Something like this

def flatten_dict(d):
    def items():
        for key, value in d.items():
            if isinstance(value, dict):
               for subkey, subvalue in flatten_dict(value).items():
                    yield subkey, subvalue
            else:
                yield key, value

    return dict(items())

this returns

{'level1_one': '1', 'level2_one': '2', 'level3_one': 'bottom'}

for the example you posted

answered Dec 5, 2017 at 17:02

RoachLord

1,0712 gold badges15 silver badges30 bronze badges

Collectives™ on Stack Overflow

Nested and flatten dictionary from JSON by using recursion

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related