how to edit values in a nested dictionary based on the key value and the nested value

Question

I'm trying to create a function that will go through a nested dictionary and add the value of a key to a nested value, and create a new nested key-value pair. So for instance this input:

current_dict = {1: {'int1': 11}, 2: {'int1': 12}, 3: {'int1': 13}, 4: {'int1': 14}, 
5: {'int1': 15}}

would look like this output:

new_dict = {1: {'int1': 11, 'int2': 12}, 2: {'int1': 12, 'int2', 14}, 
3: {'int1': 13, 'int2', 16}, 4: {'int1': 14, 'int2': 18}, 5: {'int1': 15, 'int2', 20}}

I was working with a non-nested dictionary with something similar to add key-value pairs to create a new value using this:

int_dict = {1: 11, 2: 12, 3: 13, 4: 14, 5: 15}
new_dict2 = {}

def func2(k, v):
    new_k = k + v
    return new_k

for k, v in integer_dictionary.items():
    new_dict2[k] = func2(k, v)

and returns this:

{1: 12, 2: 14, 3: 16, 4: 18, 5: 20}

Ideally I would like to build out this function to be able to handle nested dictionaries as described above, but I'm not sure how to handle iterating through the nested elements.

Answer 1

You can use a dictionary comprehension:

current_dict = {1: {'int1': 11}, 2: {'int1': 12}, 3: {'int1': 13}, 4: {'int1': 14}, 5: {'int1': 15}}
new_dict = {a:{**b, 'int2':b['int1']+a} for a, b in current_dict.items()}

Output:

{1: {'int1': 11, 'int2': 12}, 2: {'int1': 12, 'int2': 14}, 3: {'int1': 13, 'int2': 16}, 4: {'int1': 14, 'int2': 18}, 5: {'int1': 15, 'int2': 20}}

Edit: without a comprehension:

def funct2(k, v):
     return {**v, 'int2':v['int1']+k} 

for a, b in current_dict.items():
   current_dict[a] = funct2(a, b)

Output:

{1: {'int1': 11, 'int2': 12}, 2: {'int1': 12, 'int2': 14}, 3: {'int1': 13, 'int2': 16}, 4: {'int1': 14, 'int2': 18}, 5: {'int1': 15, 'int2': 20}}

Answer 2

A function that can do that could look like:

Code:

def add_new_value_from_key_value(a_dict, key_add_from, key_to_add):
    a_dict = a_dict.copy()
    for k, v in a_dict.items():
        v[key_to_add] = k + v[key_add_from]
    return a_dict

Test Code:

current_dict = {1: {'int1': 11}, 2: {'int1': 12}, 3: {'int1': 13},
                4: {'int1': 14}, 5: {'int1': 15}
                }

new_dict = {
    1: {'int1': 11, 'int2': 12},
    2: {'int1': 12, 'int2': 14},
    3: {'int1': 13, 'int2': 16},
    4: {'int1': 14, 'int2': 18},
    5: {'int1': 15, 'int2': 20}
}

print(add_new_value_from_key_value(current_dict, 'int1', 'int2'))
assert new_dict == add_new_value_from_key_value(current_dict, 'int1', 'int2')

Results:

{
    1: {'int1': 11, 'int2': 12}, 
    2: {'int1': 12, 'int2': 14}, 
    3: {'int1': 13, 'int2': 16}, 
    4: {'int1': 14, 'int2': 18}, 
    5: {'int1': 15, 'int2': 20}
}

Answer 3

This should work:

current_dict = {1: {'int1': 11}, 2: {'int1': 12}, 3: {'int1': 13}, 4: {'int1': 14}, 5: {'int1': 15}}

new_dict = current_dict.copy()

for k, v in new_dict.iteritems():
    v['int2'] = v['int1'] + k