🏦 Banking System (Python, OOP, CLI)

A multi-module banking application built in Python that simulates the core functionality of a retail bank.

🚀 Features

• Account Management

  • Open/close accounts with unique 8-digit account numbers and system-generated 4-digit PINs.
  • Secure account handling with masked SSN display.
  • Balances stored in cents to prevent floating-point errors.

• Transactions

  • Deposits & withdrawals (PIN-verified).
  • Account-to-account transfers.
  • Monthly interest accrual (APR/12), with half-up rounding for accuracy.

• ATM & Coin Handling

  • ATM cash breakdown (withdrawals return bills in $50/$20/$10/$5/$1).
  • Coin parser accepts input like 10q 3d 7n 5p and converts directly to cents.

• Menu-Driven CLI

  • Intuitive text-based interface.
  • Robust input validation and helpful error messages.

🛠️ Tech Stack

• Language: Python 3.x
• Paradigm: Object-Oriented Programming (OOP)
• Modules:
  • Account.py → Encapsulates account data (owner, SSN, PIN, balance).
  • Bank.py → Manages accounts, generates unique IDs, ensures capacity.
  • BankManager.py → Main CLI interface with transaction menus.
  • BankUtility.py → Utility functions (currency formatting, dollar→cent conversion).
  • CoinCollector.py → Regex-based coin string parser.

📂 Project Structure

BankingSystem/
│── Account.py
│── Bank.py
│── BankManager.py   # Entry point (main program)
│── BankUtility.py
│── CoinCollector.py

▶️ How to Run

1. Clone the repo:

   git clone https://github.com/your-username/BankingSystem.git
   cd BankingSystem

2. Run the manager:

   python BankManager.py

💻 Sample Usage

=== Welcome to the Bank Manager ===
1) Open Account
2) Close Account
3) Deposit
4) Withdraw
5) Transfer
6) ATM Withdrawal
7) Deposit Coins
8) Apply Monthly Interest
0) Exit

>> Selection: 1
Enter Name: John Doe
Enter SSN: 123-45-6789
Account created!
Account #: 12345678 | PIN: 4821

🌟 Future Improvements

• Add persistent storage (SQLite or JSON).
• Support multiple currencies.
• Add unit tests for core functionality.
• Enhance security (hashed PINs, encryption).

📜 License

MIT License — free to use, modify, and distribute.