Python Program to Find Largest Number in a List

Last Updated : 28 Aug, 2023

Given a list of numbers, the task is to write a Python program to find the largest number in given list.

Examples:

Input : list1 = [10, 20, 4]
Output : 20

Find Largest Number in a List with Native Example

Sort the list in ascending order and print the last element in the list.

Python3

# Python program to find largest
# number in a list
 
# list of numbers
list1 = [10, 20, 4, 45, 99]
 
# sorting the list
list1.sort()
 
# printing the last element
print("Largest element is:", list1[-1])

Output

Largest element is: 99

Time Complexity: O(nlogn)
Auxiliary Space: O(1)

Find Largest Number in a List Using max() method

Here list1 is a list with some element and we will use max() function, this will return maximum from the array.

Python3

# Python program to find largest
# number in a list
 
# List of numbers
list1 = [10, 20, 4, 45, 99]
 
# Printing the maximum element
print("Largest element is:", max(list1))

Output

Largest element is: 99

Time complexity : O(n)
Auxiliary Space : O(1)

Find the max list element on inputs provided by user

Python3

# Python program to find largest
# number in a list
 
# Creating an empty list
list1 = []
 
# asking number of elements to put in list
num = int(input("Enter number of elements in list: "))
 
# Iterating till num to append elements in list
for i in range(1, num + 1):
    ele = int(input("Enter elements: "))
    list1.append(ele)
 
# Printing maximum element
print("Largest element is:", max(list1))

Output:

Enter number of elements in list: 4
Enter elements: 12
Enter elements: 19
Enter elements: 1
Enter elements: 99
Largest element is: 99

Time complexity : O(n)
Auxiliary Space : O(1)

Find Largest Number in a List Without using built-in functions

Python3

# Python program to find largest
# number in a list
 
 
def myMax(list1):
 
    # Assume first number in list is largest
    # initially and assign it to variable "max"
    max = list1[0]
# Now traverse through the list and compare
    # each number with "max" value. Whichever is
    # largest assign that value to "max'.
    for x in list1:
        if x > max:
            max = x
 
    # after complete traversing the list
    # return the "max" value
    return max
 
 
# Driver code
list1 = [10, 20, 4, 45, 99]
print("Largest element is:", myMax(list1))

Output

Largest element is: 99

Time complexity : O(n)
Auxiliary Space : O(1)

Find Largest Number in a List Using the lambda function

Python lambda which is also know as inline function, here we will use max inside the lambda.

Python3

# python code to print largest element in the list
 
lst = [20, 10, 20, 4, 100]
print(max(lst, key=lambda value: int(value)) )

Output

Time complexity : O(n)
Auxiliary Space: O(n), where n is the length of the list.

Find Largest Number in a List Using reduce function

Using reduce() function we will get the maximum element from the array.

Python3

from functools import reduce
lst = [20, 10, 20, 4, 100]
largest_elem = reduce(max, lst)
print(largest_elem)

Output

Time Complexity: O(n)
Auxiliary Space: O(1)

Find Largest Number in a List Using recursion

Python3

# Function to find the largest element in the list
def FindLargest(itr, ele, list1):
 
  # Base condition
    if itr == len(list1):
        print("Largest element in the list is: ", ele)
        return
 
      # Check max condition
    if ele < list1[itr]:
        ele = list1[itr]
 
        # Recursive solution
    FindLargest(itr+1, ele, list1)
 
    return
 
  # input list
list1 = [2, 1, 7, 9, 5, 4]
 
FindLargest(0, list1[0], list1)

Output

Largest element in the list is:  9

Time Complexity: O(n)
Auxiliary Space: O(n)

Find Largest Number in a List Using heapq.nlargest()

Here’s how you can use heapq.nlargest() function to find the largest number in a list:

Algorithm:

Import the heapq module.
Create a list of numbers.
Use the heapq.nlargest() function to find the largest element. The nlargest() function takes two arguments – the first argument is the number of largest elements to be returned, and the second argument is the list of numbers.
Retrieve the largest element from the list of largest elements returned by heapq.nlargest() function.
Print the largest element.

Python3

import heapq
 
# list of numbers
list1 = [10, 20, 4, 45, 99]
 
# finding the largest element using heapq.nlargest()
largest_element = heapq.nlargest(1, list1)[0]
 
# printing the largest element
print("Largest element is:", largest_element)

Output

Largest element is: 99

Time complexity: O(nlogk), where n is the length of the list and k is the number of largest elements to be returned. In this case, k is 1, so the time complexity is O(nlog1) = O(n).
Auxiliary Space: O(k), where k is the number of largest elements to be returned. In this case, k is 1, so the auxiliary space is O(1).

Find Largest Number in a List Using np.max() method

Initialize the test list.
Use np.array() method to convert the list to numpy array.
Use np.max() method on numpy array which gives the max element in the list.

Python3

import numpy as np
 
# given list
list1 = [2, 7, 5, 64, 14]
 
# converting list to numpy array
arr = np.array(list1)
 
# finding largest numbers using np.max() method
num = arr.max()
 
# printing largest number
print(num)

Output:

Time Complexity: O(n) where n is the length of the list.
Auxiliary Space: O(n) where n is the length of the list. because numpy array of length n is created.

S

Shivam_k

Improve

Python program to find second largest number in a list

Similar Reads

Python Program to Print Largest Even and Largest Odd Number in a List

Auxiliary Given a list. The task is to print the largest even and largest odd number in a list. Examples: Input: 1 3 5 8 6 10 Output: Largest even number is 10 Largest odd number is 5 Input: 123 234 236 694 809 Output: Largest odd number is 809 Largest even number is 694 The first approach uses two methods , one for computing largest even number an

Python program to find second largest number in a list

Given a list of numbers, the task is to write a Python program to find the second largest number in the given list. Examples: Input: list1 = [10, 20, 4]Output: 10 Input: list2 = [70, 11, 20, 4, 100]Output: 70 Method 1: Sorting is an easier but less optimal method. Given below is an O(n) algorithm to do the same. C/C++ Code # Python program to find

Python | Largest, Smallest, Second Largest, Second Smallest in a List

Since, unlike other programming languages, Python does not have arrays, instead, it has list. Using lists is more easy and comfortable to work with in comparison to arrays. Moreover, the vast inbuilt functions of Python, make the task easier. So using these techniques, let's try to find the various ranges of the number in a given list. Examples: In

Python program to find N largest elements from a list

Given a list of integers, the task is to find N largest elements assuming size of list is greater than or equal o N. Examples : Input : [4, 5, 1, 2, 9] N = 2 Output : [9, 5] Input : [81, 52, 45, 10, 3, 2, 96] N = 3 Output : [81, 96, 52] A simple solution traverse the given list N times. In every traversal, find the maximum, add it to result, and re

Python Program for Find largest prime factor of a number

Given a positive integer \'n\'( 1 <= n <= 1015). Find the largest prime factor of a number. Input: 6 Output: 3 Explanation Prime factor of 6 are- 2, 3 Largest of them is 3 Input: 15 Output: 5 C/C++ Code # Python3 code to find largest prime # factor of number import math # A function to find largest prime factor def maxPrimeFactors (n): # Init

Python | Find frequency of largest element in list

Given a list, the task is to find the number of occurrences of the largest element of the list.Examples: Input : [1, 2, 8, 5, 8, 7, 8] Output :3 Input : [2, 9, 1, 3, 4, 5] Output :1 Method 1: The naive approach is to find the largest element present in the list using max(list) function, then iterating through the list using a for loop and find the

Python | Largest number possible from list of given numbers

Given a list of numbers, the task is to find the largest number possible from the elements given in the list. This is one of the problems that is essential in competitive point of view and this article discusses various shorthands to solve this problem in Python. Let's discuss certain ways in which this problem can be solved. Method #1 : Using sort

Get Second Largest Number in Python List Using Bubble Sort

Finding the second-largest number in a list is a common programming task that involves sorting the list in ascending order. Bubble sort is a simple sorting algorithm that can be used for this purpose. In this article, we will explore the logic behind finding the second largest number using bubble sort and provide a Python program to implement it. M

Python Program to Find Largest Item in a Tuple

Given a tuple, the task is to write a Python program to find the greatest number in a Tuple. Example: Input: (10,20,23,5,2,90) #tupleOutput: 90Explanation: 90 is the largest element from tupleValues of a tuple are syntactically separated by ‘commas’. Although it is not necessary, it is more common to define a tuple by closing the sequence of values

Python Program to Find Largest Element in an Array

To find the largest element in an array, iterate over each element and compare it with the current largest element. If an element is greater, update the largest element. At the end of the iteration, the largest element will be found. Given an array, find the largest element in it. Input : arr[] = {10, 20, 4}Output : 20Input : arr[] = {20, 10, 20, 4

Article Tags :

Practice Tags :

python