SyntaxError：非默认参数遵循默认参数； __init__ 相关[重复]

Question

这是我最后的选择。我到处搜索过，但总是与它被另一个函数或其他东西重写有关。我向你保证，没有其他函数使用这个 init 东西。我是初学者。

错误是我得到这个：SyntaxError：非默认参数遵循默认参数。它指向__init__([here]self, ...etcetc)。

class book:

def __init__(self, bookId, nextBook=None, name, author, ageGroup):
    self.bookId = bookId
    self.nextBook = nextBook
    self.name = str(name)
    self.author = str(author)
    self.ageGroup = str(ageGroup)

def getInfo(self):
    return self.bookdId

def setInfo(self, bookId, bookName, authorName, ageGroup):
    self.bookId = bookId
    self.name = bookName
    self.author = authorName
    self.ageGroup = ageGroup

def getNextBook(self):
    return self.nextBook

def setNextBook(self,val):
    self.nextBook = val

class bookCollection:

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

def getSize(self):
    return self.size

def addBookToFront(self,bookId):
    newBook = book(bookId,self.head)
    self.head = newBook
    self.size+=1
    return True

def listAllBooks(self):
    curr = self.head
    while curr:
        print(curr.data)
        print(curr.name)


        curr = curr.getNextBook()

def deleteBook(self,value):
    prev = None
    curr = self.head
    while curr:
        if curr.getInfo() == value:
            if prev:
                prev.setNextBook(curr.getNextBook())
            else:
                self.head = curr.getNextBook()
            return True     
        prev = curr
        curr = curr.getNextBook()  
    return False

def addBookAtPosition(self, newBookId, position):
    counter = 1

    if position == 0:
        newBookId.setNextBook(self.head)
        self.head = newBookId

    else:
        book = self.head
        while book.getNextBook() is not None:
            if counter == position:
                newBookId.setNextBook(book.getNextBook())
                book.setNextBook(newBookId)
            book = book.getNextBook()
            counter = counter + 1

def removeBookAtPosition(self, removedBookId, position):
    counter = 1

    if position == 0:
        self.head = removedBookId.getNextBook()

    else:
        book = self.head
        while book.getNextBook() is not None:
            if counter == position - 1:
                book.setNextBook(removedBookId.getNextBook())

            book = book.getNextBook()
            counter = counter + 1

 #for reference: bookId, bookName, authorName, ageGroup
 Boy = book(1, Boy, Roald-Dahl, Teens)

Answer 1

它在抱怨这条线：

def __init__(self, bookId, nextBook=None, name, author, ageGroup):

参数nextBook 有一个默认值，即None。 但参数 name、author 和 ageGroup 没有默认值。 这是解释器所禁止的，或者更准确地说，是解释器的解析器部分所禁止的。

要么不给 nextBook 一个默认值，要么给 name、author 和 ageGroup时间>。如果您只想为 nextBook 设置默认值，请将其设为最后一个参数，在 name、author 和 ageGroup之后>.