def issue_book(name, student_id, book_title, days): for book in Catalog.books_list: if book.title == book_title and len(book.book_item) != 0: book_item = book.book_item.pop() book.total_count -= 1 Catalog.update_member_issue_info(book_item, name, student_id, days) Catalog.add_to_issue_list(book_item) return book_item else: print(f"{book_title} is currently not available in the library")