Python – Product and Inter Summation dictionary values

Sometimes, while working with Python dictionaries, we can have a problem in which we need to perform product of entire value list and perform summation of product of each list with other. This kind of application in web development and day-day programming. Lets discuss certain ways in which this task can be performed.

Input : test_dict = {‘gfg’ : [4], ‘is’ : [3], ‘best’ : [5]}
Output : 60

Input : test_dict = {‘gfg’ : [0]}
Output : 0

Method #1 : Using zip() + map() + sum() + loop
The combination of above functions can be used to solve this problem. In this, we perform the summation of values using sum(), the zip() binds all the values. The map() is used to bind multiplication logic in all elements in value list. All this is bound using loop.

# Python3 code to demonstrate working of
# Product and Inter Summation dictionary values
# Using zip() + map() + sum() + loop

# helper function
def mul(sub):
  res = 1
  for ele in sub:
     res *= int(ele)
  return res

# initializing dictionary
test_dict = {'gfg' : [4, 5, 6], 'is' : [1, 3, 4], 'best' : [7, 8, 9]}

# printing original dictionary
print("The original dictionary : " + str(test_dict))

# Product and Inter Summation dictionary values
# Using zip() + map() + sum() + loop
temp = zip(*test_dict.values())
res = sum(map(mul, temp))

# printing result
print("The summations of product : " + str(res))

Output :

The original dictionary : {‘best’: [7, 8, 9], ‘is’: [1, 3, 4], ‘gfg’: [4, 5, 6]}
The summations of product : 364

Method #2 : Using map() + reduce() + lambda + zip() + sum() + generator expression
The combination of above functionalities can be used to solve this problem. In this, we perform the task of multiplication using reduce and lambda and generator expression performs the task of iteration.

# Python3 code to demonstrate working of
# Product and Inter Summation dictionary values
# Using map() + reduce() + lambda + zip() + sum() + generator expression
from functools import reduce

# initializing dictionary
test_dict = {'gfg' : [4, 5, 6], 'is' : [1, 3, 4], 'best' : [7, 8, 9]}

# printing original dictionary
print("The original dictionary : " + str(test_dict))

# Product and Inter Summation dictionary values
# Using map() + reduce() + lambda + zip() + sum() + generator expression
res = sum(map(lambda ele: reduce(lambda x, y: int(x) * int(y), ele),
                                          zip(*test_dict.values())))

# printing result
print("The summations of product : " + str(res))

Output :

The original dictionary : {‘best’: [7, 8, 9], ‘is’: [1, 3, 4], ‘gfg’: [4, 5, 6]}
The summations of product : 364