Question

所以我有两个类 - 一个是书库，它实现为一个双向链表，另一个类是一个书籍节点的DLL节点类，它是这样的：

class Book:
def __init__(self,name,author,dateadded,viewed = False, nextnode=None, prevnode=None):
    self._name = name
    self._author = author
    self._dateadded = dateadded
    self._viewed = viewed
    self._next = nextnode
    self._prev = prevnode

def __str__(self):
    """ Return string representation of book """
    outstr = ""
    outstr += self._name + " /n"
    outstr += self._author + "/n"
    outstr += self._dateadded
    return outstr

def read(self):
    """ Simulates the book being read & return string representation of the book """
    self._viewed = True
    outstr = "CURRENTLY READING: "
    outstr += self._name
    return outstr

我的图书馆类处理书籍节点的序列，如下所示：

class BookLibrary:

""" A Doubly Linked List implementing a book library """

def __init__(self):
    self.size = 0
    self.head = None
    self.tail = None

我遇到的问题是在我的add_book()方法中 - 当我运行它时，我得到的错误是TypeError: add_book() takes 1 positional argument but 5 were given。这是功能本身，我真的不知道我哪里出错了：（

def add_book(book):
    """ Add a book to the library in decreasing order of dateadded """
    n = Book(book)
    if self.size == 0:
        self.head = n
        self.tail = n
        current_book = n
        self.size += 1

    elif self.head._dateadded <= n._dateadded:
        n._next = self.head
        self.head._prev = n
        n._prev = None
        self.head = n
        self.size += 1

    elif self.tail._dateadded <= n._dateadded:
        self.tail._prev._next = n
        n._prev = self.tail._prev
        n._next = self.tail
        self.tail._prev = n
        self.size += 1

    elif self.size != 0:
        iterator = self.head._next
        while iterator._next is not None:
            if n._dateadded >= iterator._dateadded:
                n._prev = iterator._prev
                iterator._prev._next = n
                n._next = iterator
                iterator._prev = n
                self.size += 1
                break
            else:
                iterator = iterator._next
    return None

我真的很感谢任何帮助，谢谢你

这是我运行的代码：

book_lib = BookLibrary()
book_lib.add_book("Harry Potter", "JK ROWLING", 19990101, False)

Answer 1

如果您将add_book()的所有参数传递给class Book，那么这就是您的问题。它只期望一个参数book，但我假设你传递了class Book期望的所有参数。

最好首先实例化图书对象，然后将它们直接传递到add_book方法中。

python双向链表类

1 个答案: