Python ATM System

Overview

A command-line ATM simulation built in Python using Object-Oriented Programming, demonstrating secure banking operations across a clean three-file structure.

Project Structure

• account.py — Account class, SHA-256 PIN hashing, 3-strike lockout logic
• transaction.py — Deposit, withdrawal, EFT transfer, balance checks
• main.py — CLI entry point, registration and login flow

Features

• User registration and login with 3-strike lockout
• PIN hashing via SHA-256 (hashlib) — never stored or logged in plaintext
• Deposit, withdrawal, EFT transfer, and statement viewing
• Self-transfer prevention and funds validation
• CSV-based account persistence across sessions
• Audit logging to log.txt for all transactions
• Zero pycodestyle violations, full docstring coverage

How to Run

python main.py

What I Learned

Built with a focus on secure-by-design thinking: hashing credentials, handling authentication failure states explicitly, and maintaining an audit trail — all practices directly relevant to GRC and security-aware development.

Author

Ndumiso Mbanjwa