class Book: def __init__(self, title, book_id, price): self.title = title self.book_id = book_id self.price = price def __del__(self): print(f"Book destroyed-{self.title},{self.book_id},{self.price}") if __title="__main__": book1 = Book("Python入门", "978-7-121-33620-1", 39.99) del book1改正错误

您需要将 `if __title="__main__":` 改为 `if __name__=="__main__":`，因为 `__name__` 是一个特殊变量，用来表示当前模块的名字。当模块被直接运行时，`__name__` 的值为`__main__`，因此需要使用这个条件语句来判断是否在主程序中执行。修改后的代码如下：

class Book:
    def __init__(self, title, book_id, price):
        self.title = title
        self.book_id = book_id
        self.price = price
        
    def __del__(self):
        print(f"Book destroyed-{self.title},{self.book_id},{self.price}")

if __name__ == "__main__":
    book1 = Book("Python入门", "978-7-121-33620-1", 39.99)
    del book1