Question

在执行我的python代码时遇到此错误：

Error:  line 20, in _readBookList  
if bkID < cur_node.bkID: AttributeError: 'bookNode' object has no attribute 'bkID'

input.txt文件包含以下数据：

100,2  
101,3  
102,5

代码：

class bookNode:
    def __init__(self, bkID, availCount):
        self.bookID = bkID
        self.avCntr = availCount
        self.ChkOutCntr = 0
        self.left = None
        self.right = None

class Tree:
    def __init__(self):
        self.root = None

    def readBookList(self, bkID, availCount):
        if self.root == None:
            self.root = bookNode(bkID, availCount)
        else:
            self._readBookList(bkID,availCount,self.root)

    def _readBookList(self,bkID, availCount, cur_node):
        if bkID < cur_node.bkID:
            if cur_node.left == None:
                cur_node.left = bookNode(bkID, availCount)
                # cur_node.left_child.parent = cur_node  # set parent
            else:
                self._readBookList(bkID, availCount, cur_node.left)
        elif bkID > cur_node.bkID:
            if cur_node == None:
                cur_node = bookNode(bkID,availCount)
                # cur_node.right_child.parent = cur_node  # set parent
            else:
                self._readBookList(bkID,availCount, cur_node.right)
        else:
            print("ID already in tree!")

    def print_tree(self):
        if self.root != None:
            self._print_tree(self.root)

    def _print_tree(self, cur_node):
        if cur_node != None:
            self._print_tree(cur_node.left)
            print(cur_node.bkID)
            self._print_tree(cur_node.right)
tree = Tree()

f = open("input.txt", "r")
for x in f:
    print(x)
    bookDetails = x.split(",")
    tree.readBookList(bookDetails[0], bookDetails[1])
    # _readBookList
f.close()
tree.print_tree()

Answer 1

这是一个错字，

if bkID < cur_node.bkID:

应为：

if bkID < cur_node.bookID:

检查更新的代码：

class bookNode:
    def __init__(self, bkID, availCount):
        self.bookID = bkID
        self.avCntr = availCount
        self.ChkOutCntr = 0
        self.left = None
        self.right = None

class Tree:
    def __init__(self):
        self.root = None

    def readBookList(self, bkID, availCount):
        if self.root == None:
            self.root = bookNode(bkID, availCount)
        else:
            self._readBookList(bkID,availCount,self.root)

    def _readBookList(self,bkID, availCount, cur_node):
        if cur_node != None :
            if bkID < cur_node.bookID:
                if cur_node.left == None:
                    cur_node.left = bookNode(bkID, availCount)
                    # cur_node.left_child.parent = cur_node  # set parent
                else:
                    self._readBookList(bkID, availCount, cur_node.left)
            elif bkID > cur_node.bookID:
                if cur_node == None:
                    cur_node = bookNode(bkID,availCount)
                    # cur_node.right_child.parent = cur_node  # set parent
                else:
                    self._readBookList(bkID,availCount, cur_node.right)
            else:
                print("ID already in tree!")

    def print_tree(self):
        if self.root != None:
            self._print_tree(self.root)

    def _print_tree(self, cur_node):
        if cur_node != None:
            self._print_tree(cur_node.left)
            print(cur_node.bookID)
            self._print_tree(cur_node.right)
tree = Tree()

f = open("input.txt", "r")
for x in f:
    print(x)
    bookDetails = x.split(",")
    tree.readBookList(bookDetails[0], bookDetails[1])
    # _readBookList
f.close()
tree.print_tree()

问题出在self._readBookList(bkID,availCount, cur_node.right)行上，此处您没有检查cur_node.right是否不是None。我已经更新了。

Answer 2

问题在于您正在调用的名称是__init__的参数，而不是属性。要解决此问题，您只需将*.bkID更改为*.bookID

Answer 3

因为您拼写错误，所以cur_node没有bkID，实际上是bookID。另外，您忘记添加cur_node.right = bookNode(bkID,availCount)此行。下面是完整的代码。

class bookNode:
    def __init__(self, bkID, availCount):
        self.bookID = bkID
        self.avCntr = availCount
        self.ChkOutCntr = 0
        self.left = None
        self.right = None

class Tree:
    def __init__(self):
        self.root = None

    def readBookList(self, bkID, availCount):
        if self.root == None:
            self.root = bookNode(bkID, availCount)
        else:
            self._readBookList(bkID,availCount,self.root)

    def _readBookList(self,bkID, availCount, cur_node):
        if bkID < cur_node.bookID: #HERE
            if cur_node.left == None:
                cur_node.left = bookNode(bkID, availCount)
                # cur_node.left_child.parent = cur_node  # set parent
            else:
                self._readBookList(bkID, availCount, cur_node.left)
        elif bkID > cur_node.bookID: #HERE
            if cur_node == None:
                cur_node = bookNode(bkID,availCount)
                # cur_node.right_child.parent = cur_node  # set parent
            else:
                cur_node.right = bookNode(bkID,availCount) #ADD THIS LINE
                self._readBookList(bkID,availCount, cur_node.right)
        else:
            print("ID already in tree!")

    def print_tree(self):
        if self.root != None:
            self._print_tree(self.root)

    def _print_tree(self, cur_node):
        if cur_node != None:
            self._print_tree(cur_node.left)
            print(cur_node.bookID) #HERE
            self._print_tree(cur_node.right)
tree = Tree()

f = open("input.txt", "r")
for x in f:
    print(x)
    bookDetails = x.split(",")
    tree.readBookList(bookDetails[0], bookDetails[1])
    # _readBookList
f.close()
tree.print_tree()

AttributeError：“类”对象没有属性

3 个答案: