Classes Livro e Usuário

from book import Book

# 1. Crie um objeto Book
book = Book("1984", "George Orwell", "345678")

# 2. Verifique os atributos
print(book.title)       # Deve imprimir: 1984
print(book.author)      # Should print: George Orwell
print(book.isbn)        # Deve imprimir: 345678
print(book.available)   # Deve imprimir: True
print(book.borrower)    # Deve imprimir: None

# 3. Teste __str__ quando disponível
print(book)  # Should print: 1984 by George Orwell (ISBN: 345678) - Available

# 4. Test __str__ when not available
book.available = False
print(book)  # Should print: 1984 by George Orwell (ISBN: 345678) - Not Available