value 不能使用 class [closed] 放入列表中

问：

[book.py]

from book_info import book_lists


class Book:
    def __init__(self, books):
        self.books = books

    def book_manag(self):
        want_book = []
        while True:
            answer = input("Do you wanna borrow or return or no? (borrow/return/no) :")
            # split the cases
            if answer == "no":
                break

            elif answer == "borrow":
                bo_want_book = input("which books do you wanna borrow?:")
                want_book.append(bo_want_book)
                for book in book_lists:
                    if bo_want_book == book['title']:
                        book["status"] = "borrowed"

            elif answer == "return":
                re_want_book = input("which books do you wanna return?:")
                for book in book_lists:
                    if re_want_book == book["ti`your text`tle"]:
                        book["status"] = "available"

        return want_book


book_m = Book(book_lists)  # define class
print("\n")

for i in book_lists:
    print(i)


book_lists = book_m.book_manag()
print(f"final book Lists : {book_lists}")

[book_info]

book_lists = [{"title":"harry poter",
               "author" : "amy block",
               "ISBN" : "34567890",
               "status" : "available"},
              {"title": "hunger game",
               "author": "casy",
               "ISBN": "456787678",
               "status": "available"},
              {"title": "To Kill a Mockingbird",
               "author": "Harper Lee",
               "ISBN": "978-0-06-112008-4",
               "status": "available"},
                {"title": "1984",
                 "author": "George Orwell",
                 "ISBN": "978-0-452-28423-4",
                 "status": "available"},
                {"title": "The Great Gatsby",
                 "author": "F. Scott Fitzgerald",
                 "ISBN": "978-0-7432-7356-5",
                 "status": "available"},
                {"title": "Pride and Prejudice",
                 "author": "Jane Austen",
                 "ISBN": "978-1-85326-120-9",
                 "status": "available"},
                {"title": "The Catcher in the Rye", "author": "J.D. Salinger", "ISBN": "978-0-316-76948-7",
                 "status": "available"},
                {"title": "The Hobbit", "author": "J.R.R. Tolkien", "ISBN": "978-0-261-10280-2",
                 "status": "available"},
                {"title": "The Alchemist", "author": "Paulo Coelho",
                 "ISBN": "978-0-06-112241-5", "status": "available"},
                {"title": "The Hunger Games",
                 "author": "Suzanne Collins", "ISBN": "978-0-439-02348-1", "status": "available"},
                {"title": "The Girl with the Dragon Tattoo",
                 "author": "Stieg Larsson", "ISBN": "978-0-307-26995-8", "status": "available"},
                {"title": "Harry Potter and the Sorcerer's Stone",
                 "author": "J.K. Rowling", "ISBN": "978-0-545-01022-6", "status": "available"}
]

[customer.py]

from book import Book
from book_info import book_lists

book_m = Book(book_lists)


value = book_m.book_manag()
print(f"Books borrowed: {value}")

[说明] 在这种情况下，“值”是 []（我的意思是空的） 我想我应该得到一些字符串值（当我在“book.py”中借用并输入“哈利波特”时） 为什么。。。它是空的 我将“customer.py”连接到“book.py”。

结果是
“借阅的书籍：[]” 我不知道为什么这个结果总是空列表 我声明“return want_book”，所以我想我应该得到这部分的值 [value = book_m.book_manag（） print（f“借阅的书籍：{value}”）] 我说得对吗？