The equivalent of sum() for multiplication in Python


Borislav Hadzhiev

Last updated: Jul 4, 2022


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The equivalent of sum() for multiplication in Python #

The equivalent of sum() for multiplication is the method. The method takes an iterable and calculates the product of all elements in the iterable.
import math my_list = [2, 2, 2] result = print(result) # 👉️ 8

Make sure to import the math module.

The method calculates the product of all the elements in the provided iterable.

The method takes the following 2 arguments:

iterableAn iterable whose elements to calculate the product of
startThe start value for the product (defaults to 1)

If the iterable is empty, the start value is returned.

Note that the function is intended for use with numeric values.

If you have digits that are wrapped in strings, use the int() or float() classes to convert them to numbers first.
import math my_list = ['2', '2', '2'] result =, my_list)) print(result) # 👉️ 8

The map() function takes a function and an iterable as arguments and calls the function with each item of the iterable.

Each string in the list gets passed to the int() class and gets converted to an integer.

Alternatively, you can use the reduce() function to multiply the values in an iterable.
from functools import reduce from operator import mul my_list = [2, 2, 2] result = reduce(mul, my_list, 1) print(result) # 👉️ 8

The reduce function takes the following 3 parameters:

functionA function that takes 2 parameters - the accumulated value and a value from the iterable.
iterableEach element in the iterable will get passed as an argument to the function.
initializerAn optional initializer value that is placed before the items of the iterable in the calculation.
The reduce() function calls the provided reducer function (mul) with the accumulated value and an item from the iterable.

The mul function from the operator module is the same as a * b.

The result variable stores the multiplication result for the items in the iterable.

If the iterable is empty and the initializer argument is provided, the initializer is returned.
from functools import reduce from operator import mul my_list = [] result = reduce(mul, my_list, 1) # 👈️ initializer of 1 print(result) # 👉️ 1
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