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# Python Program to Find Second Largest Number in a List

In this Python program, weâ€™ll create a program that finds the second largest number in a list of integers. Weâ€™ll walk through the problem statement, the program itself, how it works, and provide input-output examples.

## Problem Statement:

Python Program to Find Second Largest Given a list of integers, we want to find the second largest number in the list.

## Python Program to Find Second Largest Number in a List

```def second_largest(numbers):
if len(numbers) < 2:
return "List should contain at least two numbers."

largest = second = float('-inf')

for num in numbers:
if num > largest:
second = largest
largest = num
elif num > second and num != largest:
second = num

if second == float('-inf'):
return "There is no second largest element."

return second

# Input list of numbers
num_list = [12, 45, 2, 41, 31, 10]
result = second_largest(num_list)
print("The second largest number is:", result)
```

## How it Works:

1. The function `second_largest` takes a list of numbers as input.
2. It initializes two variables `largest` and `second` with negative infinity using `float('-inf')`.
3. It iterates through each number in the list.
4. If the current number is greater than the `largest` number, it updates `second` with the value of `largest` and updates `largest` with the current number.
5. If the current number is greater than `second` and not equal to `largest`, it updates `second` with the current number.
6. After iterating through all numbers, it checks if `second` is still equal to negative infinity, which means there is no second largest element in the list.
7. Finally, the function returns the second largest number.

## Input:

`[12, 45, 2, 41, 31, 10]`

## Output:

`The second largest number is: 41`

## Input:

`[5, 5, 5, 5]`

## Output:

`There is no second largest element.`

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