getitem-2-6.py

class Book:
    def __init__(self, title, author, publication_year):
        self.title = title
        self.author = author
        self.publication_year = publication_year

    def __str__(self):
        return f"{self.title} by {self.author} ({self.publication_year})"

    def __repr__(self):
        return f"Book('{self.title}', '{self.author}', {self.publication_year})"

class Library:
    def __init__(self):
        self.books = []

    def __getitem__(self, item):
        if isinstance(item, int):
            return self.books[item]
        elif isinstance(item, str):
            matching_author = [
                book
                for book in self.books
                if item.casefold() in book.author.casefold()
            ]
            return matching_author

    def add_books(self, books):
        """
        Add books to the library
        :param books: list (or other sequence) of Book objects
        """
        self.books.extend(books)


books_data = [
    Book("To Kill a Mockingbird", "Harper Lee", 1960),
    Book("1984", "George Orwell", 1949),
    Book("Animal Farm", "George Orwell", 1945),
    Book("The Hitchhiker's Guide to the Galaxy", "Douglas Adams", 1979),
    Book("Harry Potter and the Philosopher's Stone", "J.K. Rowling", 1997),
    Book("Harry Potter and the Chamber of Secrets", "J.K. Rowling", 1998),
    Book("A Brief History of Time", "Stephen Hawking", 1988),
    Book("The Selfish Gene", "Richard Dawkins", 1976),
    Book("Cosmos", "Carl Sagan", 1980),
]

gorgeous_library = Library()
gorgeous_library.add_books(books_data)

print(gorgeous_library["Orwell"])