简单的图书馆借阅系统python

一个简单的图书馆借阅系统可以用Python实现，其中包含几个基本功能，例如添加图书、借出图书、归还图书以及查看当前的图书列表。下面是一个简单的示例代码来展示如何构建这样的系统：

class Book:
    def __init__(self, title, author, isbn):
        self.title = title
        self.author = author
        self.isbn = isbn
        self.borrowed = False

    def __str__(self):
        return f"{self.title} by {self.author}, ISBN: {self.isbn}"

class Library:
    def __init__(self):
        self.books = []

    def add_book(self, book):
        self.books.append(book)

    def borrow_book(self, isbn):
        for book in self.books:
            if book.isbn == isbn and not book.borrowed:
                book.borrowed = True
                return f"Book '{book.title}' has been borrowed."
            elif book.isbn == isbn and book.borrowed:
                return f"Book '{book.title}' is already borrowed."
        return "Book not found."

    def return_book(self, isbn):
        for book in self.books:
            if book.isbn == isbn and book.borrowed:
                book.borrowed = False
                return f"Book '{book.title}' has been returned."
        return "Book not found."

    def list_books(self):
        if not self.books:
            return "No books in the library."
        for book in self.books:
            status = "Available" if not book.borrowed else "Borrowed"
            print(f"{book} - {status}")

# 使用示例
library = Library()
library.add_book(Book("Python Programming", "John Doe", "123456789"))
library.add_book(Book("Learning AI", "Jane Smith", "987654321"))

library.list_books()  # 列出所有图书
print(library.borrow_book("123456789"))  # 借出图书
library.list_books()  # 再次列出所有图书以确认状态
print(library.return_book("123456789"))  # 归还图书
library.list_books()  # 最后列出所有图书以确认状态

这个简单的图书馆借阅系统定义了两个类：`Book` 和 `Library`。`Book` 类用来创建图书对象，包含书名、作者、ISBN号和借阅状态。`Library` 类用来管理图书，包括添加图书、借出图书、归还图书和列出所有图书的方法。