Python Finding Second Largest Number

Syntax

num_list = [2, 5, 3, 7, 13, 1, 6]
largest_num = max(num_list)
second_largest = None

for num in num_list:
    if num != largest_num:
        if second_largest is None:
            second_largest = num
        elif num > second_largest:
            second_largest = num

Example

num_list = [2, 5, 3, 7, 13, 1, 6]
largest_num = max(num_list)
second_largest = None

for num in num_list:
    if num != largest_num:
        if second_largest is None:
            second_largest = num
        elif num > second_largest:
            second_largest = num

print("The second largest number in the list is:", second_largest)

Output

The second largest number in the list is: 7

Explanation

This program finds the second largest number in a list of numbers using a for loop and conditional statements.

First, the program finds the largest number in the list using the max() function. It then initializes a variable second_largest to None.

Then, the program loops through each number in the list. If the number is not equal to the largest number in the list, the program checks if second_largest is None. If it is, the program sets second_largest to the current number. If it is not None, the program checks if the current number is greater than second_largest and updates second_largest if it is.

Finally, the program prints out the second largest number.

Use

This program is useful when you need to find the second largest number in a list of numbers in Python.

Important Points

• The max() function is used to find the largest number in the list.
• The program initializes second_largest to None to handle edge cases where the largest number appears more than once.
• The program checks if second_largest is None before updating it.

Summary

This program demonstrates how to find the second largest number in a list of numbers in Python using a for loop and conditional statements. It uses the max() function to find the largest number, initializes second_largest to None, and then loops through the list to find the second largest number.