🏦 A modern dual-interface Python banking system showcasing clean architecture, OOP, Pydantic v2 validation, SQLite persistence, secure PIN authentication, and seamless CLI + Web experiences.
PyBank lets you register customers, open secured bank accounts, perform deposits, withdrawals, transfers, close accounts, and view detailed transaction histories with passbook-style statements. Built for learning and demonstration of production-grade patterns in Python.
Status: 🚀 Early-stage educational project. Explore the Architecture Guide and User Guide for deeper insights.
- ✨ Features
- 🏗️ Project Structure
- 🚀 Getting Started
- 💻 Usage
- 🗄️ Data Model
- 📚 Documentation
- 🛠️ Development
- 📜 License
- 🖥️ Dual Interface – Intuitive terminal CLI (
main.py) and feature-rich Streamlit web UI (streamlit_app.py) - 👤 Smart Account Registration – Captures Aadhaar, personal details, and sets up secure PIN protection
- 🔐 Secure Authentication – 4-digit PINs hashed with PBKDF2-HMAC-SHA256 using unique salts
- 💵 Deposits & Withdrawals – Real-time balance updates with PIN verification and validation
- 💸 Fund Transfers – Secure transfers between accounts with atomic transactions and rollback on errors
- 🔒 Account Management – Close/deactivate accounts with PIN verification
- 📊 Balance & Profile Views – Quick balance checks and comprehensive customer/account profiles
- 📜 Transaction History – Passbook-style statement with running balances and timestamps
- ✅ Robust Validation – Pydantic v2 validates all inputs at the trust boundary
- 🗃️ Reliable Persistence – SQLite with WAL journaling, schema auto-creation, and migrations
- 🏛️ Clean Design – Singleton connection manager, enum-based routing, and layered architecture
- 🔄 Transactional Integrity – Commits on success, automatic rollback on errors
pybank/
├── main.py # 🚪 CLI application entry point
├── streamlit_app.py # 🌐 Streamlit web UI
├── pyproject.toml # 📦 Project metadata & dependencies (uv)
├── justfile # ⚡ Task recipes
├── README.md # 📖 Project documentation
├── LICENSE # ⚖️ Apache-2.0 License
├── db/ # 💾 SQLite database (auto-created)
├── docs/ # 📚 Documentation
│ ├── architecture.md
│ ├── components.md
│ ├── presentation.md
│ └── user-guide.md
├── src/
│ ├── app.py # 🔄 CLI loop & BankAction router
│ ├── const.py # 📋 DB config & menu constants
│ ├── enums.py # 🔢 BankAction enumeration
│ ├── sqlite_db.py # 🗄️ Singleton SQLite connection + schema
│ ├── validators/
│ │ └── models.py # 🛡️ Pydantic models
│ ├── handlers/
│ │ └── pybank.py # 💼 Core banking operations
│ ├── helpers/
│ │ ├── design.py # 🧬 SingletonMeta
│ │ └── security.py # 🔐 PIN hashing
│ └── utils/
│ └── cli_utils.py # 🎨 Colored output
└── tests/ # 🧪 Test suite
git clone https://github.com/anupmika/pybank.git
cd pybank
uv sync --no-cachepython main.py
# or
uv run main.py
# or
just runstreamlit run streamlit_app.py
# or
uv run streamlit run streamlit_app.py
# or
just dev-ui----------------------
| PyBank |
----------------------
| 1 | Open Account |
----------------------
| 2 | Deposite Money |
----------------------
| 3 | Withdraw Money |
----------------------
| 4 | View Balance |
----------------------
| 5 | View History |
----------------------
| 6 | Close Account |
----------------------
| 7 | View Account |
----------------------
| 8 | Transfer Money |
----------------------
| 9 | Close App |
----------------------
See User Guide for detailed walkthroughs.
| Column | Type | Constraints | Notes |
|---|---|---|---|
| id | INTEGER | PK (autoincrement) | Primary key |
| aadhar_num | TEXT | UNIQUE NOT NULL | 12-digit Aadhaar |
| name | TEXT | NOT NULL | Full name |
| TEXT | NULL | Optional | |
| phone | TEXT | NOT NULL | Phone number |
| age | INTEGER | NOT NULL | Age |
| father_name | TEXT | NOT NULL | Father's name |
| address | TEXT | NULL | Optional |
| city | TEXT | NOT NULL | City |
| initial_balance | REAL | NOT NULL | Initial deposit |
| created_at | TEXT | NOT NULL (ISO) | Created timestamp |
| Column | Type | Constraints | Notes |
|---|---|---|---|
| account_num | INTEGER | UNIQUE NOT NULL | 500000 + user_id |
| user_id | INTEGER | FK -> users(id) NOT NULL | User reference |
| account_type | TEXT | DEFAULT 'savings' | Account type |
| balance | REAL | DEFAULT 0 | Current balance |
| currency | TEXT | DEFAULT 'INR' | Currency |
| is_active | INTEGER | DEFAULT 1 | 1 active, 0 inactive |
| created_at | TEXT | NOT NULL (ISO) | Created timestamp |
| pin_hash | TEXT | NULL | PBKDF2-HMAC-SHA256 hash |
| Column | Type | Constraints | Notes |
|---|---|---|---|
| id | INTEGER | PK (autoincrement) | Primary key |
| account_num | INTEGER | FK -> accounts(account_num) | Account reference |
| transaction_type | TEXT | NOT NULL | deposit/withdraw/transfer_in/transfer_out |
| amount | REAL | NOT NULL | Amount |
| balance_after | REAL | NOT NULL | Balance after tx |
| timestamp | TEXT | NOT NULL (ISO) | Timestamp |
| Document | Description |
|---|---|
| Architecture Guide | Design patterns, layers, and flows |
| Component Reference | Module/class/function details |
| User Guide | Step-by-step usage for CLI and web |
| Presentation | Project presentation and diagrams |
just test # Run tests
just coverage # Run with coverage
just sync # Install deps
just run # CLI app
just dev-ui # Streamlit app
just clean # Clean artifactsLicensed under the Apache License 2.0. Made with ❤️ and Python 💰