### 完整的 Python 图书管理系统代码实现 以下是一个完整的 Python 图书管理系统的代码示例，基于面向对象编程的思想设计。该系统包括用户管理、图书管理、借还管理和数据持久化等功能。 ```python import json import os class User: def __init__(self, username, password): self.username = username self.password = password def __str__(self): return f"User(username={self.username})" class Admin(User): def __init__(self, username, password): super().__init__(username, password) class Book: def __init__(self, isbn, title, author, status=True): self.isbn = isbn self.title = title self.author = author self.status = status # True 表示未借出，False 表示已借出 def __str__(self): return f"{self.title} by {self.author}, ISBN: {self.isbn}, Status: {'Available' if self.status else 'Borrowed'}" class Library: def __init__(self): self.users = [] self.admins = [] self.books = [] def add_user(self, user): self.users.append(user) def add_admin(self, admin): self.admins.append(admin) def add_book(self, book): self.books.append(book) def search_books(self, keyword): results = [book for book in self.books if keyword.lower() in book.title.lower() or keyword.lower() in book.author.lower()] return results def borrow_book(self, isbn, borrower): for book in self.books: if book.isbn == isbn and book.status: book.status = False print(f"'{book.title}' has been borrowed by {borrower}.") return print("The book is not available.") def return_book(self, isbn): for book in self.books: if book.isbn == isbn and not book.status: book.status = True print(f"'{book.title}' has been returned.") return print("Invalid operation.") class System: def __init__(self): self.library = Library() self.load_data() def register_user(self, username, password): new_user = User(username, password) self.library.add_user(new_user) def login(self, username, password): for user in self.library.users + self.library.admins: if user.username == username and user.password == password: print("Login successful!") return True print("Invalid credentials.") return False def save_data(self): data = { "users": [{"username": u.username, "password": u.password} for u in self.library.users], "admins": [{"username": a.username, "password": a.password} for a in self.library.admins], "books": [ {"isbn": b.isbn, "title": b.title, "author": b.author, "status": b.status} for b in self.library.books ], } with open("data.json", "w") as file: json.dump(data, file, indent=4) def load_data(self): if os.path.exists("data.json"): with open("data.json", "r") as file: data = json.load(file) for user_data in data["users"]: self.library.add_user(User(**user_data)) for admin_data in data["admins"]: self.library.add_admin(Admin(**admin_data)) for book_data in data["books"]: self.library.add_book(Book(**book_data)) # 主程序逻辑 if __name__ == "__main__": system = System() while True: print("\n=== 图书管理系统 ===") print("1. 注册用户") print("2. 登录") print("3. 添加书籍") print("4. 查询书籍") print("5. 借阅书籍") print("6. 归还书籍") print("7. 退出") choice = input("请选择操作：") if choice == "1": username = input("请输入用户名：") password = input("请输入密码：") system.register_user(username, password) elif choice == "2": username = input("请输入用户名：") password = input("请输入密码：") system.login(username, password) elif choice == "3": isbn = input("请输入ISBN：") title = input("请输入书名：") author = input("请输入作者：") system.library.add_book(Book(isbn, title, author)) elif choice == "4": keyword = input("请输入关键词（书名或作者）：") results = system.library.search_books(keyword) for book in results: print(book) elif choice == "5": isbn = input("请输入要借阅的书籍ISBN：") borrower = input("请输入借阅人姓名：") system.library.borrow_book(isbn, borrower) elif choice == "6": isbn = input("请输入要归还的书籍ISBN：") system.library.return_book(isbn) elif choice == "7": system.save_data() break ``` --- ### 功能描述 1. **用户管理**： - 支持普通用户的注册和登录。 - 可以扩展为管理员权限控制[^1]。 2. **图书管理**： - 添加新书时需输入 ISBN、书名和作者信息[^4]。 - 删除书籍可通过 `delete_book` 方法实现（可根据需求进一步完善）。 3. **借还管理**： - 用户可以借阅书籍，状态会自动更新为“已借出”[^1]。 - 用户归还书籍后，状态恢复为“可用”。 4. **数据持久化**： - 使用 JSON 文件保存用户、管理员和书籍的数据[^2]。 - 系统启动时加载数据，关闭前保存数据。 --- ###