Python Nested Dictionary

10 Feb, 2022
Prerequisite – Python dictionaryA Dictionary in Python works similar to the Dictionary in the real world. Keys of a Dictionary must be unique and of immutable data type such as Strings, Integers and tuples, but the key-values can be repeated and be of any type.Nested Dictionary: Nesting Dictionary means putting a dictionary inside another dictionary. Nesting is of great use as the kind of information we can model in programs is expanded greatly.  
Python3
nested_dict = { 'dict1': {'key_A': 'value_A'},                'dict2': {'key_B': 'value_B'}}
Python3
# As shown in image # Creating a Nested DictionaryDict = {1: 'Geeks', 2: 'For', 3: {'A' : 'Welcome', 'B' : 'To', 'C' : 'Geeks'}}
In Python, a Nested dictionary can be created by placing the comma-separated dictionaries enclosed within braces.  
Python3
# Empty nested dictionaryDict = { 'Dict1': { },         'Dict2': { }}print("Nested dictionary 1-")print(Dict) # Nested dictionary having same keysDict = { 'Dict1': {'name': 'Ali', 'age': '19'},         'Dict2': {'name': 'Bob', 'age': '25'}}print("\nNested dictionary 2-")print(Dict) # Nested dictionary of mixed dictionary keysDict = { 'Dict1': {1: 'G', 2: 'F', 3: 'G'},         'Dict2': {'Name': 'Geeks', 1: [1, 2]} }print("\nNested dictionary 3-")print(Dict)
Output: 
Nested dictionary 1-
{'Dict1': {}, 'Dict2': {}}

Nested dictionary 2-
{'Dict1': {'name': 'Ali', 'age': '19'}, 'Dict2': {'name': 'Bob', 'age': '25'}}

Nested dictionary 3-
{'Dict1': {1: 'G', 2: 'F', 3: 'G'}, 'Dict2': {1: [1, 2], 'Name': 'Geeks'}}
 
Addition of elements to a nested Dictionary can be done in multiple ways. One way to add a dictionary in the Nested dictionary is to add values one be one, Nested_dict[dict][key] = ‘value’. Another way is to add the whole dictionary in one go, Nested_dict[dict] = { ‘key’: ‘value’}.  
Python3
Dict = { }print("Initial nested dictionary:-")print(Dict) Dict['Dict1'] = {} # Adding elements one at a timeDict['Dict1']['name'] = 'Bob'Dict['Dict1']['age'] = 21print("\nAfter adding dictionary Dict1")print(Dict) # Adding whole dictionaryDict['Dict2'] = {'name': 'Cara', 'age': 25}print("\nAfter adding dictionary Dict1")print(Dict)
Output:  
Initial nested dictionary:-
{}

After adding dictionary Dict1
{'Dict1': {'age': 21, 'name': 'Bob'}}

After adding dictionary Dict1
{'Dict1': {'age': 21, 'name': 'Bob'}, 'Dict2': {'age': 25, 'name': 'Cara'}}
 
In order to access the value of any key in nested dictionary, use indexing [] syntax.  
Python3
# Nested dictionary having same keysDict = { 'Dict1': {'name': 'Ali', 'age': '19'},         'Dict2': {'name': 'Bob', 'age': '25'}} # Prints value corresponding to key 'name' in Dict1print(Dict['Dict1']['name']) # Prints value corresponding to key 'age' in Dict2print(Dict['Dict2']['age'])
Output:  
Ali
25
 
Deletion of dictionaries from a nested dictionary can be done either by using del keyword or by using pop() function.  
Python3
Dict = {'Dict1': {'name': 'Ali', 'age': 19},        'Dict2': {'name': 'Bob', 'age': 21}}print("Initial nested dictionary:-")print(Dict) # Deleting dictionary using del keywordprint("\nDeleting Dict2:-")del Dict['Dict2']print(Dict) # Deleting dictionary using pop functionprint("\nDeleting Dict1:-")Dict.pop('Dict1')print (Dict)
Output:  
Initial nested dictionary:-
{'Dict2': {'name': 'Bob', 'age': 21}, 'Dict1': {'name': 'Ali', 'age': 19}}

Deleting Dict2:-
{'Dict1': {'name': 'Ali', 'age': 19}}

Deleting Dict1:-
{}
 
rkbhola5
python-dict
Python-nested-dictionary
Python
python-dict
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.