medium Object-Oriented Programming

Library Loan Tracker

The Brief

Worcester County Library is replacing its ancient loans system. They have asked you to build the core domain logic in Python: books, members, loans, returns, and overdue fines.

Loan period is 14 days. Late fees are 50p per day after that, capped at £10 per book. A member cannot borrow a book that is already on loan. The system needs to report every loan a member currently holds and total outstanding fines.

Acceptance Criteria

Tap a criterion to mark it off as you work. Tap a category header to expand or collapse.

1 Array

2 Array

3 Array

4 Array

💡 Hints 0 / 5

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solution.py

Python 3

from datetime import date, timedelta


class Book:
    def __init__(self, title, author, isbn):
        # TODO: store fields, default on_loan = False
        pass


class Member:
    def __init__(self, name, member_id):
        # TODO: store fields, init current_loans = {}, fine_balance = 0.0
        pass


class Library:
    LOAN_DAYS = 14
    DAILY_FINE = 0.50
    MAX_FINE = 10.00

    def __init__(self):
        # TODO: storage for books and members
        pass

    def add_book(self, book):
        pass

    def add_member(self, member):
        pass

    def borrow(self, member_id, isbn, today):
        # TODO: validate, mark on_loan, record loan_date
        pass

    def return_book(self, member_id, isbn, today):
        # TODO: compute fine if overdue, cap at MAX_FINE
        pass

    def member_summary(self, member_id):
        # TODO: return dict with loans + total_fines
        pass

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