Digital Library

Python console app that simulates a small library workflow: add/search books, borrow/return, and persist state to JSON.

The image is a portfolio overview generated from the real OOP model. The application itself remains a CLI project, which keeps the focus on domain modeling, state transitions, persistence, and tests.

Additional visual references:

• docs/images/Library_Shop.png: terminal workflow capture.
• docs/images/educational_flow.svg: learning flow from CLI usage to OOP and JSON persistence.

Why This Project Matters

This project demonstrates foundational backend skills in a compact scope:

• object-oriented domain modeling
• deterministic state transitions
• persistence and reload behavior
• automated tests for core logic
• structured snapshot data that could later support a GUI or API layer

Core Features

• Add, list, and search books
• Borrow and return flows with availability checks
• Save and load library state from library_data.json
• Generate a simple operational report
• Produce a structured snapshot() summary for review or future UI/API use

Architecture

• Book, Reader, Library classes define the domain model.
• A menu-driven CLI orchestrates user actions.
• JSON persistence keeps data durable between sessions.

Proof of Work

• Tests verify borrow/return state changes and persistence behavior.
• The CLI can be run without external services, accounts, or API keys.
• snapshot() gives a structured view that could later feed a UI or API layer.

Difficult Parts / Tradeoffs

• The project stays intentionally small so OOP fundamentals are easy to inspect.
• JSON is used instead of a database because the goal is domain modeling and persistence basics.
• The CLI is simple by design; the value is in predictable state transitions and tests.

Tech Stack

Python, JSON, pytest.

Quick Start

python digital_library.py

Demo Flow

1) Add a new book
2) Borrow that book
3) Save data to JSON
4) Restart app and load JSON
5) Confirm state is preserved

Example Output (trimmed)

Books in Central Library:
 - The Little Prince - Antoine de Saint-Exupery - available

==== LIBRARY REPORT ====
Total books: 3
Available books: 2
Borrowed books: 1

Tests

python -m pytest

Project Structure

digital-library/
+-- digital_library.py
+-- library_data.json
+-- tests/
+-- docs/

Development Timeline

• Core implementation: OOP model, borrow/return rules, JSON persistence, and tests.
• Recent polish: screenshot refresh and README restructuring for clearer technical review.

Notes

• library_data.json can be edited to preload a custom catalog.
• The app starts with a small demo dataset for quick validation.

Engineering Notes

See docs/ENGINEERING_NOTES.md for technical rationale, build-vs-polish context, and learning notes.