Day 29: Python Program to Reverse of a Number

 

Line-by-Line Explanation

1. Function Definition

def reverse_a_number(number):

Defines a function named reverse_a_number that takes a single parameter called number.

This function will be used to reverse the digits of the input number.

2. Reverse the Number

   reversed_a_number = int(str(number)[::-1])

Convert number to string:

str(number): Converts the input integer number into a string. For example, if number = 123, this would become the string "123".

Reverse the string:

[::-1]: This slicing operation reverses the string. It works by starting at the end of the string and working backwards.

Convert the reversed string back into an integer:

int(...): Converts the reversed string back into an integer type.

Assign to a variable:

The reversed number is stored in the variable reversed_a_number.

3. Return the Reversed Number

    return reversed_a_number

The function returns the reversed number (converted back into an integer) to wherever the function is called.

4. Input from the User

number = int(input("Enter a number:"))

input("Enter a number:"):

Displays the prompt "Enter a number:" to the user.

Convert the input string into an integer:

int(input(...)): Converts the user's input (which is initially a string) into an integer type.

Store the integer in the variable number.

5. Call the Function

reversed_a_num = reverse_a_number(number)

The reverse_a_number() function is called with the user-provided input (number) as an argument.

The result (the reversed number) is stored in the variable reversed_a_num.

6. Print the Result

print(f"The reverse of {number} is {reversed_a_num}.")

f-string for string formatting:

f"The reverse of {number} is {reversed_a_num}." dynamically inserts the original number and its reversed counterpart into the output string.

{number}: Displays the original number entered by the user.

{reversed_a_num}: Displays the reversed number computed by the function.

The reverse of 123 is 321.