Python | Sort dictionary by value list length

While working with Python, one might come to a problem in which one needs to perform a sort on dictionary list value length. This can be typically in case of scoring or any type of count algorithm. Let’s discuss a method by which this task can be performed.

Method : Using sorted() + join() + lambda
The combination of above functions can be used to perform this particular task. In this, we just use the lambda function to perform this particular task, sorted and join function perform the required sorting and encapsulation of result respectively.





# Python3 code to demonstrate working of
# Sort dictionary by value list length
# using sorted() + join() + lambda
# Initialize dictionary
test_dict = {'is' : [1, 2], 'gfg' : [3], 'best' : [1, 3, 4]}
# Printing original dictionary
print("The original dictionary is : " + str(test_dict))
# using sorted() + join() + lambda
# Sort dictionary by value list length
res = ' '.join(sorted(test_dict, key = lambda key: len(test_dict[key])))
# printing result 
print("Sorted keys by value list : " + res)


Output :

The original dictionary is : {'is': [1, 2], 'best': [1, 3, 4], 'gfg': [3]}
Sorted keys by value list : gfg is best

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