An array is a data structure that stores elements and each element is recognized by its index.
In this Answer, we will learn how to find the product of array elements in Python using the following methods:
The math.prod() function
The numpy.prod() function
For a given arr = [2,4,7,9,10], to find the product of the elements in the array, we need to:
Define a variable for our result and name it the product.
Assign the value 1 to the variable.
Iterate through the array.
Multiply the variable with the iterator, num.
Store the result in the variable product.
The Python program is as follows:
arr = [2,4,7,9,10]product = 1# for loopfor num in arr:product = product * num# display the resultprint(product)
Line 1: We create the variable arr, and assign an array of 5 elements to the variable.
Line 2: We create the variable product, and assign the value 1 to the variable. This is done because any value multiplied with 1 returns the same value.
Line 5: We iterate through the array.
Line 6: For each iteration, we multiply the element and store it in the variable, product.
Line 8: We use the print() method to display the result to the console.
math.prod()methodWe now have a new technique to calculate the product of array elements: math.prod().
The math.prod() method is used in calculating the product of all elements present in a given iterable like tuples and lists.
Note: The list can be referred to as an array. To make use of the
math.prod()method, we must have upgraded our Python installation to version 3.8.
The Python program to find the product of array elements using the math.prod() method is given below:
# import the math libraryimport matharr = [2,4,7,9,10]product = math.prod(arr)# display the resultprint(product)
Line 2: We import the math library to make use of mathematical functions, constants, etc.
Line 3: We assign an array to a variable, arr.
Line 4: We use math.prod() method to calculate the product of array elements and assign it to a variable, product.
Line 6: We use the print() method to print the result to the console.
numpy.prod()methodThe numpy.prod() method is a method in the numpy library which is used to calculate the product of array elements of a given axis.
If the axis is negative, the product is calculated from the last to the first axis. For an axis assigned with a value of 0, the product is calculated along the column, and an axis with a value of 1, the product is calculated along the row.
The Python program to find the product of array elements using the numpy.prod() method is given below:
# import the numpy library as npimport numpy as nparr = [2,4,7,9,10]product = np.prod(arr)#display resultprint(product)
Line 2: We import the numpy library as np to create an alias of the library. The numpy library enables high mathematical functions to be performed on arrays and matrices.
Line 4: We assign an array to a variable, arr .
Line 5: We use numpy.prod() method to calculate the product of array elements and assign it to a variable, product. By default, our axis is 0. The product of the array will be calculated along the column.
Line 7: We use the print() method to print the result to the console.
We can also find the product of a multi-dimensional array using the numpy.prod() method.
The Python program to find the product of a two-dimensional array using the numpy.prod() method is given below:
import numpy as nparr = [[4,3,2], [5,2,1]]product = np.prod(arr, axis=1)print(product)
Line 3: We assign a two-dimensional array to a variable, arr.
Line 4: We use the numpy.prod() method to calculate the product of array elements and assign it to a variable, product. We assign 1 to our axis, this will calculate the product along the row.
Line 6: We use the print() method to print the result to the console.