Check Palindrome Number in Python

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 Python Check Palindrome Number: A palindrome number is a number that remains the same when its digits are reversed. In other words, it reads the same forwards and backwards

Example – 11, 131, 222

Note – Leading zeros are not counted in a palindrome. For example, “010” is not considered a palindrome because it reads the same as “10” without leading zeros.

Python Program to check Palindrome Numbers

You can check if a number is a palindrome in Python by reversing the number and comparing it to the original number. If they are the same, the number is a palindrome.

  • Convert the number to a string, reverse the string, and compare it to the original string.
  • Use mathematical operations to reverse the number and compare it to the original number.

Algorithm

This algorithm works by converting the number to a string, reversing the string, and then comparing it to the original string to determine if it’s a palindrome. If the reversed string is the same as the original string, the number is considered a palindrome

  1. Define the is_palindrome function with a single argument num,
  2. Inside the function, convert the number num to a string using the str() function.
  3. Reverse the string by using slicing with [::-1].
  4. Compare the original string num_str with the reversed string reversed_str to check if they are the same.
  5. If the original string and the reversed string are the same, return True. Otherwise, return False.
  6. In the main part of the code, prompt the user to input a number using input(). The input is then converted to an integer using int() and stored in the variable num.
  7. Call the is_palindrome function with the input number num.
  8. If the function returns True, print a message indicating that the number is a palindrome. Otherwise, print a message indicating that it’s not a palindrome

Source code

In this code, we first convert the number to a string using str(), then use slicing ([::-1]) to reverse the string. Finally, we compare the original string with the reversed string to determine if the number is a palindrome

def is_palindrome(num):
    num_str = str(num)
    
    reversed_str = num_str[::-1]
    
    if num_str == reversed_str:
        return True
    else:
        return False

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

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

Steps to write Program

Step-1: Define a function named is_palindrome that takes one parameter, num.

def is_palindrome(num):

Step-2: Convert the input number num into a string and store it in the variable num_str.

num_str = str(num)

Step-3: Create a new string called reversed_str by reversing the characters in num_str.

reversed_str = num_str[::-1]

Step-4: Check if the num_str and reversed_str strings are the same. If they are equal, return True; otherwise, return False.

if num_str == reversed_str:
    return True
else:
    return False

Step-5: Input a number from the user and store it in the variable num using the input() function.

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

Step-6: Call the is_palindrome function with the input number num as an argument and check if it returns True or False. If is_palindrome(num) returns True, print that the input number is a palindrome. Otherwise, print that it is not a palindrome.

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

Output

The output of the code depends on the input you provide. Let’s go through a couple of examples to see the possible outputs:

If you input the number 12321, which is a palindrome. The code correctly identifies it as a palindrome and prints the message “12321 is a palindrome.”

Enter a number: 12321
12321 is a palindrome.

you input the number 45678, which is not a palindrome. The code correctly identifies it as not a palindrome and prints the message “45678 is not a palindrome.”

Enter a number: 45678
45678 is not a palindrome.