Skip to content
Open
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 50 additions & 0 deletions palindrome.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
"""
palindrome_number.py
Simple beginner program to check whether an integer is a palindrome.

Usage:
python3 palindrome_number.py # interactive input
python3 palindrome_number.py 121 # runs for the given number (optional argument)
"""

import sys

def is_palindrome_number(n: int) -> bool:
"""
Return True if integer n is a palindrome (reads same forwards and backwards).

Works for non-negative integers. Example: 121 -> True, 123 -> False.
"""
if n < 0:
return False # negative numbers have a leading '-' so we treat them as not palindrome
original = n
reversed_num = 0
while n > 0:
digit = n % 10
reversed_num = reversed_num * 10 + digit
n //= 10
return original == reversed_num

def main():
# Allow optional command-line argument: python3 palindrome_number.py 121
if len(sys.argv) > 1:
try:
value = int(sys.argv[1])
except ValueError:
print("Please provide a valid integer.")
return
else:
# Interactive input
try:
value = int(input("Enter an integer to check palindrome: ").strip())
except ValueError:
print("Invalid input. Please enter an integer.")
return

if is_palindrome_number(value):
print(f"{value} is a palindrome number ✅")
else:
print(f"{value} is NOT a palindrome number ❌")

if __name__ == "__main__":
main()