Python | Summation of dictionary list values
Sometimes, while working with Python dictionaries, we can have it’s values as lists. In this can we can have a problem that we just require the count of elements in those list as a whole. This can be a problem in Data Science in which we need to get total records in observations. Let’s discuss certain ways in which this task can be performed.
Method #1 : Using sum() + list comprehension
This task can be performed using sum function which can be used to get the summation and internal list comprehension can provide a mechanism to iterate this logic to all the keys of dictionary.
# Python3 code to demonstrate working of# Summation of dictionary list values# using sum() + list comprehension # initialize dictionarytest_dict = {'gfg' : [5, 6, 7], 'is' : [10, 11], 'best' : [19, 31, 22]} # printing original dictionaryprint("The original dictionary is : " + str(test_dict)) # Summation of dictionary list values# using sum() + list comprehensionres = sum(len(sub) for sub in test_dict.values()) # printing resultprint("Summation of dictionary list values are : " + str(res)) |
The original dictionary is : {'best': [19, 31, 22], 'is': [10, 11], 'gfg': [5, 6, 7]}
Summation of dictionary list values are : 8
Method #2 : Using sum() + map()
This task can also be performed using map function in place of list comprehension to extend the logic of finding the length, rest all the functionality remaining same as the above method.
# Python3 code to demonstrate working of# Summation of dictionary list values# using sum() + map() # initialize dictionarytest_dict = {'gfg' : [5, 6, 7], 'is' : [10, 11], 'best' : [19, 31, 22]} # printing original dictionaryprint("The original dictionary is : " + str(test_dict)) # Summation of dictionary list values# using sum() + map()res = sum(map(len, test_dict.values())) # printing resultprint("Summation of dictionary list values are : " + str(res)) |
The original dictionary is : {'best': [19, 31, 22], 'is': [10, 11], 'gfg': [5, 6, 7]}
Summation of dictionary list values are : 8
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