In this article, we will discuss a Python program to reverse a number. The Python programming language is renowned for its simplicity and versatility, and the task of reversing a number is no exception. We will delve into this topic by first discussing the problem statement, then explaining an algorithm for achieving this task, and finally providing a complete Python code example with an explanation of its components.

## Problem Statement

Given an integer as input, the task is to write a Python program that reverses the number. For example, if the input is **`12345`**, the output should be **`54321`**.

## Algorithm

Here is a simple algorithm for reversing a number:

- Initialize a variable
**`reverse`**as**`0`**. - Use a while loop to repeatedly perform the following steps until the number becomes
**`0`**. - In each iteration, use the modulus operator
**`%`**to get the last digit of the number. - Multiply
**`reverse`**by**`10`**and add the last digit to reverse. - Remove the last digit from the number using floor division
**`//`**.

By following this algorithm, you will extract each digit from the original number from right to left (i.e., in reverse order), and construct the reversed number.

## Python Code

Let’s take a look at a Python code snippet that accomplishes this:

1 2 3 4 5 6 7 8 9 10 11 | def reverse_number(n): reverse = 0 while n > 0: last_digit = n % 10 reverse = reverse * 10 + last_digit n = n // 10 return reverse num = 12345 print("The original number is:", num) print("The reversed number is:", reverse_number(num)) |

## Explanation of the Code

The code above defines a function called **`reverse_number()`** that takes an integer **`n`** as an argument.

Within the function, we initialize reverse to **`0`**. This variable will store the reversed number.

Next, a while loop is used to iterate until **`n`** becomes **`0`**. Inside the loop:

- We first calculate the last digit of
**`n`**using the modulus operator**`%`**. This operator returns the remainder of**`n`**divided by**`10`**, which is the last digit of**`n`**. - We then multiply reverse by
**`10`**and add the last digit. This effectively appends the last digit to**`reverse`**. - Finally, we remove the last digit from
**`n`**using floor division**`//`**. This operator returns the quotient of**`n`**divided by**`10`**, with any decimal part discarded. As a result, the last digit of**`n`**is removed.

Once the loop finishes, the function returns reverse, which is the reversed number.

The last part of the code simply calls the function with the input number **`12345`**, and then prints the original number and the reversed number.

## Conclusion

Python’s simplicity and power make it easy to write a program to reverse a number, using only basic arithmetic operations and a while loop. By understanding and following the discussed algorithm and code, you can reverse any given number. You can use this program as a basis for solving more complex problems, such as checking if a number is a palindrome.

Remember, practice is key when it comes to learning and improving your Python programming skills. Keep practicing and happy coding!