Python – Cumulative product of dictionary value lists

Last Updated : 23 Jan, 2020

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 product 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 loop + list comprehension
This task can be performed using explicit product function which can be used to get the product and internal list comprehension can provide a mechanism to iterate this logic to all the keys of dictionary.

# Python3 code to demonstrate working of
# Cummulative product of dictionary value lists
# using loop + list comprehension
  
def prod(val) :     
    res = 1         
    for ele in val:         
        res *= ele         
    return res
  
# initialize dictionary
test_dict = {'gfg' : [5, 6, 7], 'is' : [10, 11], 'best' : [19, 31, 22]}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# Cummulative product of dictionary value lists
# using loop + list comprehension
res = sum(prod(sub) for sub in test_dict.values())
  
# printing result
print("Product of dictionary list values are : " + str(res))

Output :

The original dictionary is : {'best': [19, 31, 22], 'gfg': [5, 6, 7], 'is': [10, 11]}
Product of dictionary list values are : 13278

Method #2 : Using loop + map()
This task can also be performed using map function in place of list comprehension to extend the logic of finding the product, rest all the functionality remaining same as the above method.

# Python3 code to demonstrate working of
# Cummulative product of dictionary value lists
# using loop + map()
  
def prod(val) :     
    res = 1         
    for ele in val:         
        res *= ele         
    return res
  
# initialize dictionary
test_dict = {'gfg' : [5, 6, 7], 'is' : [10, 11], 'best' : [19, 31, 22]}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# Cummulative product of dictionary value lists
# using loop + map()
res = sum(map(prod, test_dict.values()))
  
# printing result
print("Product of dictionary list values are : " + str(res))

Output :

The original dictionary is : {'best': [19, 31, 22], 'gfg': [5, 6, 7], 'is': [10, 11]}
Product of dictionary list values are : 13278

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Python – Cumulative product of dictionary value lists