Library-Management-OOP

API Documentation

Table of Contents

1. Models
   • Book
   • Member
   • Library
2. Services
   • StorageService
3. Configuration
   • Settings
4. Exceptions

---

Models

Book

Represents a book in the library system.

Constructor

Book(title: str, author: str, isbn: str, category: BookCategory = BookCategory.OTHER, publication_year: Optional[int] = None)

Parameters:

• title: The title of the book
• author: The author of the book
• isbn: The ISBN number (validated)
• category: The book category (default: OTHER)
• publication_year: The publication year (optional)

Raises:

• InvalidISBNError: If the ISBN is invalid

Properties

• title (str): The book’s title
• author (str): The book’s author
• isbn (str): The book’s ISBN
• category (BookCategory): The book’s category
• publication_year (Optional[int]): Publication year
• borrower (Optional[Member]): Current borrower
• borrowed_date (Optional[datetime]): When the book was borrowed
• due_date (Optional[datetime]): When the book is due

Methods

is_available() -> bool

Check if the book is available for borrowing.

is_overdue() -> bool

Check if the book is overdue.

days_overdue() -> int

Get the number of days the book is overdue.

borrow(member: Member, loan_period_days: int = 14) -> None

Mark the book as borrowed by a member.

return_book() -> None

Mark the book as returned.

to_dict() -> dict

Convert the book to a dictionary representation.

---

Member

Represents a library member.

Constructor

Member(name: str, email: str, member_id: str, max_books: int = 5)

Parameters:

• name: The member’s name
• email: The member’s email address (validated)
• member_id: Unique member identifier
• max_books: Maximum books the member can borrow (default: 5)

Raises:

• InvalidEmailError: If the email is invalid

Properties

• name (str): The member’s name
• email (str): The member’s email
• member_id (str): Unique identifier
• membership_date (datetime): When the member joined
• max_books (int): Maximum borrowing limit

Methods

can_borrow() -> bool

Check if the member can borrow more books.

borrow_book(book: Book) -> None

Borrow a book from the library.

Raises:

• BookNotAvailableError: If the book is not available
• ValueError: If the member has reached their borrowing limit

return_book(book: Book) -> None

Return a borrowed book.

Raises:

• BookNotBorrowedError: If the book was not borrowed by this member

get_borrowed_books() -> List[Book]

Get the list of books currently borrowed.

has_overdue_books() -> bool

Check if the member has any overdue books.

get_overdue_books() -> List[Book]

Get the list of overdue books.

calculate_late_fees(fee_per_day: float = 0.50) -> float

Calculate total late fees for overdue books.

get_details() -> str

Get a string representation of the member’s details.

to_dict() -> dict

Convert the member to a dictionary representation.

---

Library

Represents the library system.

Constructor

Library(name: str = "Library")

Parameters:

• name: The name of the library

Properties

• name (str): The library’s name
• created_date (datetime): When the library was created

Book Management Methods

add_book(book: Book) -> None

Add a book to the library.

Raises:

• DuplicateBookError: If a book with the same ISBN already exists

remove_book(isbn: str) -> Book

Remove a book from the library.

Raises:

• BookNotFoundError: If the book is not found

get_book(isbn: str) -> Book

Get a book by ISBN.

Raises:

• BookNotFoundError: If the book is not found

find_books_by_title(title: str, exact: bool = False) -> List[Book]

Find books by title.

find_books_by_author(author: str, exact: bool = False) -> List[Book]

Find books by author.

find_books_by_category(category: BookCategory) -> List[Book]

Find books by category.

get_all_books() -> List[Book]

Get all books in the library.

get_available_books() -> List[Book]

Get all available books.

get_borrowed_books() -> List[Book]

Get all borrowed books.

get_overdue_books() -> List[Book]

Get all overdue books.

Member Management Methods

add_member(member: Member) -> None

Add a member to the library.

Raises:

• DuplicateMemberError: If a member with the same ID already exists

remove_member(member_id: str) -> Member

Remove a member from the library.

Raises:

• MemberNotFoundError: If the member is not found
• ValueError: If the member has borrowed books

get_member(member_id: str) -> Member

Get a member by ID.

Raises:

• MemberNotFoundError: If the member is not found

find_members_by_name(name: str, exact: bool = False) -> List[Member]

Find members by name.

get_all_members() -> List[Member]

Get all members in the library.

get_members_with_overdue_books() -> List[Member]

Get all members with overdue books.

Statistics Methods

get_statistics() -> Dict[str, int]

Get library statistics.

Returns a dictionary containing:

• total_books: Total number of books
• available_books: Number of available books
• borrowed_books: Number of borrowed books
• overdue_books: Number of overdue books
• total_members: Total number of members
• members_with_overdue: Number of members with overdue books

to_dict() -> dict

Convert the library to a dictionary representation.

---

Services

StorageService

Service for persisting library data to JSON files.

Constructor

StorageService(storage_path: Optional[Path] = None)

Parameters:

• storage_path: Path to storage file (default: ./data/library_data.json)

Methods

save_library(library: Library) -> None

Save the library data to a JSON file.

Raises:

• IOError: If there’s an error writing to the file

load_library() -> Optional[Library]

Load library data from a JSON file.

Returns:

• Library instance or None if file doesn’t exist

Raises:

• IOError: If there’s an error reading from the file
• ValueError: If the data is invalid

delete_storage() -> None

Delete the storage file.

storage_exists() -> bool

Check if the storage file exists.

---

Configuration

Settings

Configuration settings for the library system.

Constructor

Settings(
    library_name: str = "City Library",
    max_books_per_member: int = 5,
    loan_period_days: int = 14,
    late_fee_per_day: float = 0.50,
    storage_path: str = "data/library_data.json"
)

Class Methods

load_from_file(config_path: Path) -> Settings

Load settings from a JSON configuration file.

load_or_default(config_path: Optional[Path] = None) -> Settings

Load settings from a file or return default settings.

Instance Methods

save_to_file(config_path: Path) -> None

Save settings to a JSON configuration file.

---

Exceptions

LibraryException

Base exception class for all library-related exceptions.

BookNotAvailableError

Raised when attempting to borrow a book that is not available.

BookNotFoundError

Raised when a requested book is not found in the library.

MemberNotFoundError

Raised when a requested member is not found in the library.

InvalidISBNError

Raised when an invalid ISBN is provided.

InvalidEmailError

Raised when an invalid email address is provided.

DuplicateBookError

Raised when attempting to add a book that already exists.

DuplicateMemberError

Raised when attempting to add a member that already exists.

BookNotBorrowedError

Raised when attempting to return a book that was not borrowed by the member.

---

Usage Examples

Basic Example

from library_system import Library, Book, Member, BookCategory

# Create library
library = Library("My Library")

# Add a book
book = Book("1984", "George Orwell", "9780451524935", BookCategory.FICTION, 1949)
library.add_book(book)

# Add a member
member = Member("John Doe", "john@example.com", "M001")
library.add_member(member)

# Borrow a book
member.borrow_book(book)

# Return a book
member.return_book(book)

Advanced Example with Persistence

from pathlib import Path
from library_system import Library, Book, Member
from library_system.services import StorageService
from library_system.config import Settings

# Load settings
settings = Settings.load_or_default(Path("config/library_config.json"))

# Create storage service
storage = StorageService(Path(settings.storage_path))

# Load or create library
library = storage.load_library() or Library(settings.library_name)

# ... perform operations ...

# Save library
storage.save_library(library)

This site is open source. Improve this page.