Python Program to Check if a Number is a Palindrome

num = input("Enter a number: ")

if num == num[::-1]:
    print(f"{num} is a palindrome.")
else:
    print(f"{num} is not a palindrome.")

1. num = input("Enter a number: ")

• Purpose: Prompts the user to input a number.
• Result: Stores the user’s input as a string in the variable num.
• Example: If the user enters 121, then num is "121" (a string, not an integer).

2. if num == num[::-1]:

• Purpose: Compares the string num with its reverse (num[::-1]).
• num[::-1]: This uses Python slicing to reverse the string.

Syntax:

• [::-1]: Start from the end of the string and move backward (reverse the order).

Example:

• If num = "121", then num[::-1] = "121".
• If num = "123", then num[::-1] = "321".

Comparison:

• If num is the same as num[::-1], the input is a palindrome.
• Otherwise, it is not a palindrome.

3. print(f"{num} is a palindrome.")

• If the condition num == num[::-1] is True, this statement is executed.

Example:

• Input: "121"
• Output: 121 is a palindrome.

4. else: print(f"{num} is not a palindrome.")

• If the condition num == num[::-1] is False, this statement runs.

Example:

• Input: "123"
• Output: 123 is not a palindrome.