Python Program to get Maximum product of elements of list in a 2D list
Last Updated :
22 Jan, 2025
Given a 2D list, we need to find the maximum product of elements for each list within the 2D list and determine which list yields the highest product. The goal is to efficiently compute the product of elements and identify the list with the maximum product.
Using loop with prod from math
This method calculates the product of each list using the prod function from the math module.
Python
from math import prod
# Initializing the 2D list
a = [[2, 3, 5], [1, 4, 2], [6, 1, 1]]
# Initializing variables to store the maximum product and corresponding list
max_product = 0
max_list = []
# Calculating the product of each list
for b in a:
p = prod(b) # Finding product using prod function
if p > max_product: # Checking if current product is the maximum
max_product = p
max_list = b # Updating the list with the maximum product
print(max_list, max_product)
Explanation:
- The prod function simplifies the product calculation for each sublist.
- We maintain variables to track the maximum product and the corresponding list.
Let's explore some more methods and see how to get maximum product of elements of list in 2D.
Using list comprehension
This method uses list comprehension to calculate the product of each sublist and then determines the maximum.
Python
from math import prod
# Initializing the 2D list
a = [[2, 3, 5], [1, 4, 2], [6, 1, 1]]
# Calculating the maximum product and the corresponding list
products = [prod(b) for b in a] # List comprehension to calculate product of each sublist
max_index = products.index(max(products)) # Finding the index of the maximum product
print(a[max_index], products[max_index])
Explanation:
- A list comprehension is used to store the product of each sublist.
- The index of the maximum product is identified and used to fetch the corresponding list.
This method uses reduce() from functools to compute the product for each sublist.
Python
from functools import reduce
# Initializing the 2D list
a = [[2, 3, 5], [1, 4, 2], [6, 1, 1]]
# Initializing variables to store the maximum product and corresponding list
max_product = 0
max_list = []
# Calculating the product of each list using reduce
for b in a:
p = reduce(lambda x, y: x * y, b) # Using reduce to compute the product
if p > max_product: # Checking if current product is the maximum
max_product = p
max_list = b # Updating the list with the maximum product
print(max_list, max_product)
Explanation:
- The reduce() function applies a lambda function to compute the product of each sublist.
- This method is concise but less intuitive compared to the previous ones.
Using numpy.prod
This method uses the prod function from the numpy library to compute the product.
Python
import numpy as np
# Initializing the 2D list
a = [[2, 3, 5], [1, 4, 2], [6, 1, 1]]
# Initializing variables to store the maximum product and corresponding list
max_product = 0
max_list = []
# Calculating the product of each list using numpy.prod
for b in a:
p = np.prod(b) # Calculating product using numpy.prod
if p > max_product: # Checking if current product is the maximum
max_product = p
max_list = b # Updating the list with the maximum product
print(max_list, max_product)
Explanation: numpy.prod computes numpy.prod computes the product efficiently, but importing the library increases overhead.
Using nested loops
This method calculates the product manually by multiplying the elements in each list.
Python
# Initializing the 2D list
a = [[2, 3, 5], [1, 4, 2], [6, 1, 1]]
# Initializing variables to store the maximum product and corresponding list
max_product = 0
max_list = []
# Calculating the product of each list manually
for b in a:
p = 1 # Initializing product
for x in b:
p *= x # Multiplying elements
if p > max_product: # Checking if current product is the maximum
max_product = p
max_list = b # Updating the list with the maximum product
print(max_list, max_product)
Explanation:
- Each element in the sublist is multiplied to calculate the product.
- The maximum product and corresponding list are tracked in variables.
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