Add a new dict to a existing dictionary as a value to the key

Question

I have a dictionary:

my_dict = {
    "apples":"21",
    "vegetables":"30",
    "sesame":"45",
    "papaya":"18",
}

I want to generate a new one that will look like this:

my_dict = {
    "apples" : {"apples":"21"},
    "vegetables" : {"vegetables":"30"},
    "sesame" : {"sesame":"45"},
    "papaya" : {"papaya":"18"},
}

I wrote a code like this ....

my_dict = {
    "apples":"21",
    "vegetables":"30",
    "sesame":"45",
    "papaya":"18",
}

new_dict={}
new_value_for_dict={}

for key in my_dict:
    new_value_for_dict[key]= my_dict[key]
    new_dict[key]= new_value_for_dict
    # need to clear the last key,value of the "new_value_for_dict"

print(new_dict)

And the output comes as this:

{'vegitables':{'vegitables': '30', 'saseme': '45', 
               'apples': '21','papaya': '18'},
 'saseme':{'vegitables': '30', 'saseme': '45', 
           'apples': '21', 'papaya': '18'}, 
 'apples': {'vegitables': '30', 'saseme': '45', 
            'apples': '21', 'papaya': '18'}, 
 'papaya': {'vegitables': '30', 'saseme': '45', 
            'apples': '21', 'papaya': '18'}
}

But is not how I expected. How do eliminate the repetition ? How do I get it corrected ?

You are re-using the same dictionary over and over. Create a copy if you don't want to share it, or better yet, **create a new dictionary in the loop**. — Martijn Pieters, Jul 13 '17 at 07:37

Eric Duminil · Answer 1 · 2017-07-13T07:42:06.433

You could simply create a new dict with a comprehension:

>>> {k:{k:v} for k,v in my_dict.items()}
{'sesame': {'sesame': '45'}, 'vegetables': {'vegetables': '30'}, 'papaya': {'papaya': '18'}, 'apples': {'apples': '21'}}

I don't see any reason to do so, though. You don't get more information but it becomes harder to iterate over the dict values or retrieve information.

As mentioned by @AshwiniChaudhary in the comments, you could simply move new_value_for_dict={} inside the loop in order to recreate a new inner-dict at each iteration:

my_dict = {
    "apples":"21",
    "vegetables":"30",
    "sesame":"45",
    "papaya":"18",
}

new_dict={}

for key in my_dict:
    new_value_for_dict={}
    new_value_for_dict[key]= my_dict[key]
    new_dict[key]= new_value_for_dict

print(new_dict)

Thank you for the suggestion ! – Kaushik Roy Jul 13 '17 at 08:53 — Kaushik Roy, Jul 13 '17 at 08:53

score 2 · Answer 2 · answered Jul 13 '17 at 07:40

2

almost there

for key in my_dict:
...     my_dict[key]={key:my_dict.get(key)}

answered Jul 13 '17 at 07:40

Eliethesaiyan

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Add a new dict to a existing dictionary as a value to the key

2 Answers2