Replace a dictionary key from a list

Question

Let’s say I have the following list:

my_list= ['aa', 'bb', 'cc']

My dictionary:

my_dict = {'source':{'new_key': {'k1': 1, 'k2': 2, 'k3': 3}}}

I would like to replace the new_key value in the dictionary with the list value my_list and I would like to get the following three dictionaries

{'source':{'aa': {'k1': 1, 'k2': 2, 'k3': 3}}}

{'source':{'bb': {'k1': 1, 'k2': 2, 'k3': 3}}}

{'source':{'cc': {'k1': 1, 'k2': 2, 'k3': 3}}}

I have tried the following

for i in my_list:
    my_dict ['source'][f'{i}'] = my_dict ['sources']['new_key']
    del my_dict ['source']['new_key']

Asked By: Hiwot

||

Source

Answer 1

The issue is that you keep modifying the only existing dict instance, but you need new dict, and keep the original one as base

You need to make a deep copy of the original, modify it, and save it

from copy import deepcopy

my_list = ['aa', 'bb', 'cc']
my_dict = {'source': {'new_key': {'k1': 1, 'k2': 2, 'k3': 3}}}

result = []
for item in my_list:
    value = deepcopy(my_dict)
    value['source'][item] = value['source']['new_key']
    del value['source']['new_key']
    result.append(value)

print(result)

[{'source': {'aa': {'k1': 1, 'k2': 2, 'k3': 3}}}, 
 {'source': {'bb': {'k1': 1, 'k2': 2, 'k3': 3}}},
 {'source': {'cc': {'k1': 1, 'k2': 2, 'k3': 3}}}]

If there is only this change to do, you can simplify the code

result = []
for item in my_list:
    result.append({'source': {item: deepcopy(my_dict['source']['new_key'])}})

Answered By: azro

Answer 2

You need to make a deep copy of the dictionary to be able to modify each of them separately

from copy import deepcopy

my_list= ['aa', 'bb', 'cc']
my_dict = {'source': {'new_key': {'k1': 1, 'k2': 2, 'k3': 3}}}

outdicts = {}

for l in my_list:
    outdicts[l] = deepcopy(my_dict)
    outdicts[l]['source'][l] = outdicts[l]['source'].pop('new_key')

print(f"{outdicts['aa'] = }")
print(f"{outdicts['bb'] = }")
print(f"{outdicts['cc'] = }")

Answered By: matszwecja

Answer 3

Here’s how you create the dictionaries. What you do with them is up to you:

USE_DEEPCOPY = False # change as needed

if USE_DEEPCOPY:
    from copy import deepcopy
else:
    def deepcopy(v):
        return v

my_dict = {'source':{'new_key': {'k1': 1, 'k2': 2, 'k3': 3}}}

my_list= ['aa', 'bb', 'cc']

v = my_dict['source']['new_key']

for k in my_list:
    d = {'source':{k: deepcopy(v)}}
    print(d)

Output:

{'source': {'aa': {'k1': 1, 'k2': 2, 'k3': 3}}}
{'source': {'bb': {'k1': 1, 'k2': 2, 'k3': 3}}}
{'source': {'cc': {'k1': 1, 'k2': 2, 'k3': 3}}}

Answered By: Stuart

Replace a dictionary key from a list

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