Skip to content
Related Articles

Related Articles

Improve Article
Save Article
Like Article

Python – Convert Nested dictionary to Mapped Tuple

  • Difficulty Level : Hard
  • Last Updated : 03 Jul, 2020

Sometimes, while working with Python dictionaries, we can have a problem in which we need to convert nested dictionaries to mapped tuple. This kind of problem can occur in web development and day-day programming. Let’s discuss certain ways in which this task can be performed.

Input : test_dict = {‘gfg’ : {‘x’ : 5, ‘y’ : 6, ‘z’: 3}, ‘best’ : {‘x’ : 8, ‘y’ : 3, ‘z’: 5}}
Output : [(‘x’, (5, 8)), (‘y’, (6, 3)), (‘z’, (3, 5))]

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

Input : test_dict = {‘gfg’ : {‘x’ : 5, ‘y’ : 6, ‘z’: 3}}
Output : [(‘x’, (5, )), (‘y’, (6, )), (‘z’, (3, ))]



Method #1 : Using list comprehension + generator expression
The combination of above functions can be used to solve this problem. In this, we perform the tasks of creating the tuple using list comprehension and generator expression helps in grouping, by extracting values using values().




# Python3 code to demonstrate working of 
# Convert Nested dictionary to Mapped Tuple
# Using list comprehension + generator expression
  
# initializing dictionary
test_dict = {'gfg' : {'x' : 5, 'y' : 6}, 'is' : {'x' : 1, 'y' : 4},
                                      'best' : {'x' : 8, 'y' : 3}}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# Convert Nested dictionary to Mapped Tuple
# Using list comprehension + generator expression
res = [(key, tuple(sub[key] for sub in test_dict.values())) 
                               for key in test_dict['gfg']]
  
# printing result 
print("The grouped dictionary : " + str(res)) 
Output :

The original dictionary is : {‘gfg’: {‘x’: 5, ‘y’: 6}, ‘is’: {‘x’: 1, ‘y’: 4}, ‘best’: {‘x’: 8, ‘y’: 3}}
The grouped dictionary : [(‘x’, (5, 1, 8)), (‘y’, (6, 4, 3))]

 

Method #2 : Using defaultdict() + loop
This is yet another way in which this task can be performed. In this, we perform the task of mapping using defaultdict(), of keys of nested dictionaries and recreate value list using loop. This method is useful for older version of Python.




# Python3 code to demonstrate working of 
# Convert Nested dictionary to Mapped Tuple
# Using defaultdict() + loop
from collections import defaultdict    
  
# initializing dictionary
test_dict = {'gfg' : {'x' : 5, 'y' : 6}, 'is' : {'x' : 1, 'y' : 4}, 
                                      'best' : {'x' : 8, 'y' : 3}}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# Convert Nested dictionary to Mapped Tuple
# Using defaultdict() + loop
res = defaultdict(tuple)
for key, val in test_dict.items():
    for ele in val:
        res[ele] += (val[ele], )
  
# printing result 
print("The grouped dictionary : " + str(list(res.items())) 
Output :

The original dictionary is : {‘gfg’: {‘x’: 5, ‘y’: 6}, ‘is’: {‘x’: 1, ‘y’: 4}, ‘best’: {‘x’: 8, ‘y’: 3}}
The grouped dictionary : [(‘x’, (5, 1, 8)), (‘y’, (6, 4, 3))]




My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!