Python - Filter dictionary values in heterogenous dictionary

Python – Filter dictionary values in heterogenous dictionary

Last Updated : 10 May, 2020

Sometimes, while working with Python dictionaries, we can have a problem in which we need to filter out certain values based on certain condition on a particular type, e.g all values smaller than K. This task becomes complex when dictionary values can be heterogenous. This kind of problem can have applications across many domains. Let’s discuss certain ways in which this task can be performed.

Input : test_dict = {‘Gfg’ : 10, ‘for’ : ‘geeks’}
Output : {‘Gfg’: 10, ‘for’: ‘geeks’}
Input : test_dict = {‘Gfg’ : ‘geeks’}
Output : {‘Gfg’: ‘geeks’}

Method #1 : Using type() + dictionary comprehension
The combination of above functions can be used to perform this task. In this, we check for integral type using type() and filter the data in dictionary comprehension.

# Python3 code to demonstrate working of 
# Filter dictionary values in heterogenous dictionary
# Using type() + dictionary comprehension
  
# initializing dictionary
test_dict = {'Gfg' : 4, 'is' : 2, 'best' : 3, 'for' : 'geeks'}
  
# printing original dictionary
print("The original dictionary : " + str(test_dict))
  
# initializing K 
K = 3
  
# Filter dictionary values in heterogenous dictionary
# Using type() + dictionary comprehension
res = {key : val for key, val in test_dict.items()
                   if type(val) != int or val > K}
  
# printing result 
print("Values greater than K : " + str(res)) 

Output :

The original dictionary : {'Gfg': 4, 'for': 'geeks', 'is': 2, 'best': 3}
Values greater than K : {'Gfg': 4, 'for': 'geeks'}

Method #2 : Using isinstance() + dictionary comprehension
The combination of above functions can also be used to solve this problem. In this, we perform this task similar to above, but difference being that type test is done by isintance() rather than type().

# Python3 code to demonstrate working of 
# Filter dictionary values in heterogenous dictionary
# Using isinstance() + dictionary comprehension
  
# initializing dictionary
test_dict = {'Gfg' : 4, 'is' : 2, 'best' : 3, 'for' : 'geeks'}
  
# printing original dictionary
print("The original dictionary : " + str(test_dict))
  
# initializing K 
K = 3
  
# Filter dictionary values in heterogenous dictionary
# Using isinstance() + dictionary comprehension
res = {key : val for key, val in test_dict.items() 
           if not isinstance(val, int) or val > K}
  
# printing result 
print("Values greater than K : " + str(res)) 

Output :

The original dictionary : {'Gfg': 4, 'for': 'geeks', 'is': 2, 'best': 3}
Values greater than K : {'Gfg': 4, 'for': 'geeks'}

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

My Personal Notes

Related Articles