Function to dynamically extract values from multiple nested dictionary in Python

Question

The problem statement is to write a function which will take a input dictionary object and return a list of all the values, even in case of multi-level nested dictionaries inside the input dictionary object.

Example of such a nested dictionary below:

{
    "f_name": "AKASH",
    "s_name": "NASH",
    "professional": {
        "designation": "DE",
        "company": "XYZ",
        "place_of_work": {
            "city": "BLR",
            "state": "KA",
            "country": "IN"
        }
    },
    "personal_address": {
        "city": "EKM",
        "state": "KL",
        "country": "IN"
    }
}

I did write the below code and I am able to extract the dictionary values, even incase of one nested dictionary by means of manual conditional if statement.

def dic_values(x):
    l =[]
    l1 = []
    if type(x) == dict:
        for i in x:
            if type(x[i]) != dict:
                l.append(x[i])
            elif type(x[i])== dict:
                y = x[i]
                for j in y:
                    l1.append(y[j])
    else:
        "Please input a dict object"
    l.extend(l1)
    return l

CASE 1:
On running the function with a dict object with one nested dictionary inside:

dic_values({"name":"AKASH","s_name":"NASH", "place":{"city":"BLR","state":"KA","country":"IN"}})

The Expected Output:

['AKASH', 'NASH', 'BLR', 'KA', 'IN']

CASE 2:
Like the below example, on having an input of multi-level nested dictionaries inside:

dic_values({"f_name":"AKASH","s_name":"NASH","professional":{"designation":"DE","company":"XYZ","place_of_work":{"city":"BLR","state":"KA","country":"IN"}}, "personal_address":{"city":"EKM","state":"KL","country":"IN"}})

The Output:

['AKASH','NASH','DE','XYZ', {'city': 'BLR', 'state': 'KA', 'country': 'IN'}, 'EKM', 'KL', 'IN']

Expected Output:

['AKASH','NASH','DE','XYZ', 'BLR', 'KA', 'IN', 'EKM', 'KL', 'IN']

QUESTION:
Say there were nested dictionaries present inside the input dictionary object. I would like to write a code, where the code dynamically checks for multi-level nested dictionary presence and executes. Like incase of CASE 2 Expected output.

Asked By: Saheen AHZAN

||

Source

Answer 1

def all_dict_values(input_dict):
    result = []
    for value in input_dict.values():
        if isinstance(value, dict):
            result.extend(all_dict_values(value))
        else:
            result.append(value)
    return result

Answered By: Davi A. Sampaio

Answer 2

modify your existing code to recursively call the dic_values:

def dic_values(x):
    if not isinstance(x, dict):
        return [x]
    res = []
    for v in x.values():
        res.extend(dic_values(v))
    return [v for v in res if not isinstance(v, dict)]

Answered By: Phoenix

Answer 3

In case you are interested in doing this in a non-recursive way. You can maintaining a stack of dicts as you go. So long as the stack has dicts in it there are more values to find:

def dic_values(d):
    assert isinstance(d, dict), "Please pass a dict"
    
    values = [] # this will hold the values
    stack = [d] # this should only contain dicts 
    
    while stack:
        next_d = stack.pop()
        for v in next_d.values():
            if isinstance(v, dict):
                stack.append(v) # put it back to process more
            else:
                values.append(v) # this a not dict, add it to the return list
    return values
        
        
dic_values({"f_name":"AKASH","s_name":"NASH","professional":{"designation":"DE","company":"XYZ","place_of_work":{"city":"BLR","state":"KA","country":"IN"}}, "personal_address":{"city":"EKM","state":"KL","country":"IN"}})
# ['AKASH', 'NASH', 'EKM', 'KL', 'IN', 'DE', 'XYZ', 'BLR', 'KA', 'IN']

Answered By: Mark

Function to dynamically extract values from multiple nested dictionary in Python

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