💳 Card Validator

A simple Python script to validate credit or debit card numbers using the Luhn Algorithm and identify the card type (e.g., Visa, MasterCard, American Express, LankaPay, UnionPay).

📦 Features

• Command-line interface with a formatted welcome message
• Supports card numbers with spaces or dashes
• Automatically cleans and reverses the input
• Uses the Luhn Algorithm for validation
• Identifies card type:
  • ✅ Visa
  • ✅ MasterCard
  • ✅ American Express
  • ✅ UnionPay
  • ✅ LankaPay

🧠 How It Works

1. User enters a card number.
2. The input is cleaned (spaces/dashes removed).
3. The number is reversed and processed.
4. The Luhn Algorithm calculates the checksum.
5. If valid, the card type is displayed.

🧰 Technologies Used

• Python 3

▶️ How to Run

Requirements

• Python 3.x

Steps

1. Save the script as card_validator.py
2. Open a terminal in the script’s directory
3. Run the script using:

python card_validator.py

📝 Example

==============================
|        Card Validator      |
==============================

Welcome! Let's validate your card number.

Please follow the instructions below:
- Enter your credit or debit card number.
- You can include spaces or dashes, but they will be automatically removed.
- Example: 4111 1111 1111 1111 or 4111-1111-1111-1111

Enter your credit or debit card number: 4111 1111 1111 1111
✅ Valid Card - Visa

Would you like to validate another card? (yes/no): no

Thank you for using Card Validator! Goodbye.

🔢 Example Test Card Numbers

Card Type	Example Number
Visa	4111 1111 1111 1111
MasterCard	5555 5555 5555 4444
American Express	3782 822463 10005
UnionPay	6200 0000 0000 0005
LankaPay	3571110000000000

⚠️ These are test numbers and do not work for real transactions.