Ausleihsystem

Teil des Abschnitts Object Oriented Programming der Python-Journey von Coddy — Lektion 57 von 64.

Aufgabe

Mittel

In dieser Herausforderung wirst du die Ausleihfunktionalität zum Bibliotheksverwaltungssystem hinzufügen.

Bearbeite library.py und implementiere die borrow_book-Methode gemäß den TODO-Kommentaren.

Die anderen Dateien werden dir zur Verfügung gestellt und sind gesperrt:

book.py — die Book-Klasse, die du in der vorherigen Herausforderung erstellt hast
user.py — die User-Klasse, die user_id, name und books_borrowed enthält
driver.py — führt die Test-Szenarien gegen deine Implementierung aus

borrow_book(book_isbn, user_id) muss genau eines der folgenden Ergebnisse zurückgeben: "Book not found", "User not found", "Book is not available" oder "Book borrowed successfully".

Probier es selbst

from book import Book
from user import User
from library import Library

# Umfassender Testfall-Handler
test_case = input()

# Grundlegende Funktionalitätstests
if test_case == "borrow_success":
    library = Library("Community Library")
    
    # Bücher und Benutzer hinzufügen
    book = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    library.add_book(book)
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Buch ausleihen
    result = library.borrow_book("123456", "U001")
    print(result)
    print(f"Book available: {book.available}")
    print(f"Books borrowed by user: {len(user.books_borrowed)}")

elif test_case == "book_not_found":
    library = Library("Community Library")
    user = User("U001", "Alice")
    library.add_user(user)
    
    result = library.borrow_book("nonexistent", "U001")
    print(result)

elif test_case == "user_not_found":
    library = Library("Community Library")
    book = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    library.add_book(book)
    
    result = library.borrow_book("123456", "nonexistent")
    print(result)
    
elif test_case == "book_not_available":
    library = Library("Community Library")
    
    # Bücher und Benutzer hinzufügen
    book = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    book.available = False  # Buch ist bereits ausgeliehen
    library.add_book(book)
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Try to borrow unavailable book
    result = library.borrow_book("123456", "U001")
    print(result)

# Randfälle und zusätzliche Tests
elif test_case == "multiple_books":
    library = Library("Community Library")
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Mehrere Bücher erstellen
    books = [
        Book("Book 1", "Author 1", "111"),
        Book("Book 2", "Author 2", "222"),
        Book("Book 3", "Author 3", "333")
    ]
    
    for book in books:
        library.add_book(book)
    
    # Mehrere Bücher ausleihen
    results = []
    for book in books:
        results.append(library.borrow_book(book.isbn, "U001"))
    
    for result in results:
        print(result)
    
    print(f"Total books borrowed: {len(user.books_borrowed)}")

elif test_case == "multiple_users":
    library = Library("Community Library")
    book = Book("Popular Book", "Famous Author", "999")
    library.add_book(book)
    
    # Mehrere Benutzer erstellen
    users = [
        User("U001", "Alice"),
        User("U002", "Bob"),
        User("U003", "Charlie")
    ]
    
    for user in users:
        library.add_user(user)
    
    # Versuchen, dasselbe Buch mit verschiedenen Benutzern auszuleihen
    result1 = library.borrow_book("999", "U001")
    result2 = library.borrow_book("999", "U002")  # Sollte fehlschlagen
    
    print(result1)
    print(result2)
    print(f"Book's borrower: {book.borrower.name}")

elif test_case == "return_book":
    library = Library("Community Library")
    book = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    library.add_book(book)
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Das Buch ausleihen
    borrow_result = library.borrow_book("123456", "U001")
    print(borrow_result)
    
    # Buchstatus überprüfen
    print(f"Book available: {book.available}")
    print(f"Book borrower: {book.borrower.name}")
    print(f"User's borrowed books: {len(user.books_borrowed)}")
    print(f"First borrowed book title: {user.books_borrowed[0].title}")

elif test_case == "empty_library":
    library = Library("Empty Library")
    result = library.borrow_book("any_isbn", "any_user_id")
    print(result)

elif test_case == "borrower_reference":
    library = Library("Community Library")
    book = Book("The Great Gatsby", "F. Scott Fitzgerald", "123456")
    library.add_book(book)
    
    user = User("U001", "Alice")
    library.add_user(user)
    
    # Das Buch ausleihen
    library.borrow_book("123456", "U001")
    
    # Referenzen überprüfen
    print(f"Book's borrower name: {book.borrower.name}")
    print(f"First book in user's borrowed list: {user.books_borrowed[0].title}")