Project 2 – 📚 Library Management System

1. Learning Goals

• Design a mini-database with CSV files
• Model many-to-many (members ↔ loans)
• Practise login, roles, password hashing
• Implement CRUD operations & due-date logic

2. System Roles

Role Permissions Librarian add / delete books, register members, issue/return, view overdue Member search catalogue, check availability, see own loan history

3. File Schema

File	Columns	Example Line
books.csv	ISBN,Title,Author,CopiesTotal,CopiesAvailable	9780132350884,Clean Code,Robert C. Martin,5,3
members.csv	MemberID,Name,PasswordHash,Email,JoinDate	1001,Ananya Singh,$2b$12$...Q3,ananya@mail.com,2025-05-10
loans.csv	LoanID,MemberID,ISBN,IssueDate,DueDate,ReturnDate	42,1001,9780132350884,2025-05-15,2025-05-29,

🔐 Hash passwords with bcrypt (pip install bcrypt).

4. Step-by-Step Build Plan

Phase Tasks 4.1 Setup models.py (Book, Member, Loan dataclasses) & storage.py (CSV read/write helpers). 4.2 Auth auth.py with register_member() & login(role). Store logged-in user in session dict. 4.3 Librarian Menu

1. Add book 2) Remove book 3) Issue book 4) Return book 5) View overdue list 6) Logout. 4.4 Member Menu
2. Search catalogue (title / author keyword) 2) Borrow book (if available) 3) My loans 4) Logout. 4.5 Business Rules Issue: decrement CopiesAvailable, create loan, due = issue+14d.  Return: fill ReturnDate, increment copies. 4.6 Overdue Report Select loans where ReturnDate='' and DueDate < today; pretty-print table, e-mail reminder optional. 4.7 Validation & Errors

• Invalid ISBN - Duplicate member IDs - Negative copies - Password mismatch. 4.8 Tests pytest tests/test_issue_return.py (issue then return restores availability). 4.9 Argparse --data-dir ./data flag to load CSVs from custom folder.

5. Console Snapshot

=== Librarian Dashboard ===

1. Add Book
2. Register Member
3. Issue Book
4. Return Book
5. Overdue List
6. Logout

3 ISBN to issue: 9780132350884 Member ID: 1001 ✔ Book issued. Due on 29-May-2025.