利用python写一个图书管理系统

好的，下面是一个简单的图书管理系统的代码示例，你可以根据自己的需求进行修改和完善。

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

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

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

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

    def remove_book(self, book):
        self.books.remove(book)

    def search_books(self, title=None, author=None, isbn=None):
        results = []
        for book in self.books:
            if title and title.lower() in book.title.lower():
                results.append(book)
            elif author and author.lower() in book.author.lower():
                results.append(book)
            elif isbn and isbn == book.isbn:
                results.append(book)
        return results

    def check_out(self, book):
        if not book.checked_out:
            book.checked_out = True
            return True
        else:
            return False

    def check_in(self, book):
        if book.checked_out:
            book.checked_out = False
            return True
        else:
            return False

# 示例代码
if __name__ == "__main__":
    library = Library()

    book1 = Book("The Hitchhiker's Guide to the Galaxy", "Douglas Adams", "9780345391803")
    book2 = Book("1984", "George Orwell", "9780451524935")
    book3 = Book("To Kill a Mockingbird", "Harper Lee", "9780446310789")

    library.add_book(book1)
    library.add_book(book2)
    library.add_book(book3)

    results = library.search_books(title="the")
    for result in results:
        print(result)

    library.check_out(book1)
    print(book1.checked_out)

    library.check_in(book1)
    print(book1.checked_out)

这个图书管理系统包含两个类，一个是 `Book` 类，用于表示一本书的基本信息和是否被借出，另一个是 `Library` 类，用于管理所有的书籍，包括添加、删除、搜索、借出和归还等功能。在示例代码中，我们先创建了三本书，然后添加到图书馆中，接着通过关键字搜索图书，借出其中一本书并检查它的借出状态，最后归还该书并再次检查它的借出状态。