# 1. Introduction

Finding the largest number in a list is one of the most basic algorithms in computer science. This operation is widely used in areas where data analysis or number theory is involved. Python provides several methods to accomplish this, with the max() function being one of the most direct ways.

## Definition

The largest number in a list refers to the maximum numerical value contained in the list. The task is to iterate through the list elements and identify the highest value.

# 2. Program Steps

1. Initialize a list of numbers.

2. Determine the largest number using Python's built-in max() function or by implementing a loop to check each number.

3. Print the largest number found in the list.

# 3. Code Program

``````# Initialize a list of numbers
numbers_list = [4, 12, 43, 7, 5, 9, 21]

# Use the max function to find the largest number
largest_number = max(numbers_list)

# Print the largest number
print(f"The largest number in the list is: {largest_number}")

# Alternative method: Initialize a variable to store the largest number
largest = numbers_list[0]

# Loop through the list and compare each number to find the largest
for number in numbers_list:
if number > largest:
largest = number

# Print the largest number found by the loop
print(f"The largest number found by the loop is: {largest}")
``````

### Output:

```The largest number in the list is: 43
The largest number found by the loop is: 43
```

### Explanation:

1. numbers_list is a list containing seven numerical elements.

2. max(numbers_list) is called to find the largest number in numbers_list, which is assigned to largest_number.

3. The first print statement outputs the result from the max() function.

4. In the alternative method, largest is initialized to the first element of numbers_list.

5. A for loop iterates over each number in numbers_list. If number is greater than largest, largest is updated to that number.

6. The second print statement outputs the largest number found by the loop. Both methods confirm that the largest number in numbers_list is 43.