为了创建一个简单的图书信息管理系统的Python应用程序，我们可以使用类来代表图书，以及一些基本的数据结构来存储图书列表。下面是实现这个系统的一些关键部分： ```python import json class Book: def __init__(self, id, title, author): self.id = id self.title = title self.author = author self.__title_set = set() # 用于检查标题是否已存在 @property def title(self): return self._title @title.setter def title(self, value): if value not in self.__title_set: self._title = value self.__title_set.add(value) else: raise ValueError("Title already exists.") def __str__(self): return f"Book({self.id}, {self.title}, {self.author})" class Library: def __init__(self): self.books = [] def add_book(self, book): self.books.append(book) def remove_book(self, id): for book in self.books: if book.id == id: self.books.remove(book) break def modify_book(self, old_id, new_title=None, new_author=None): for i, book in enumerate(self.books): if book.id == old_id: if new_title: book.title = new_title if new_author: book.author = new_author break def search_books(self, title=None, author=None): result = [] for book in self.books: if (not title or book.title == title) and (not author or book.author == author): result.append(book) return result def show_all_books(self): return "\n".join(str(book) for book in self.books) def save_to_file(self, filename="books.json"): with open(filename, "w", encoding="utf-8") as f: json.dump([book.__dict__ for book in self.books], f, indent=4) def exit(self): print("Exiting the library management system.") sys.exit(0) # 主程序入口 def main(): library = Library() while True: print("1. Add book") print("2. Remove book by ID") print("3. Modify book by ID") print("4. Search books") print("5. Show all books") print("6. Save to file") print("7. Exit") choice = int(input("Your choice: ")) if choice == 1: # 添加图书... elif choice == 2: # 删除图书... elif choice == 3: # 修改图书... elif choice == 4: # 搜索图书... elif choice == 5: # 显示所有图书... elif choice == 6: library.save_to_file() elif choice == 7: library.exit() else: print("Invalid choice.") if __name__ == "__main__": main() ``` 注意：这里使用了`sys`模块的`exit()`函数来模拟系统退出功能，实际项目中应处理异常情况或使用更优雅的方式退出。