所以我对编程很新，我试图在我的二叉搜索树中删除功能，以删除节点深度最高的一侧。但是，一旦我尝试运行它，我就会一直收到错误，我知道这是一个简单的修复，但在这里阅读了几个类似的问题之后我无法弄明白。
这是我的错误：
C:\Python33\python.exe "C:/Users/koopt_000/Desktop/College/Sophomore Semester 2/Computer Science 231/Chapter7/Test.py"
Traceback (most recent call last):
File "C:/Users/koopt_000/Desktop/College/Sophomore Semester 2/Computer Science 231/Chapter7/Test.py", line 10, in <module>
a.delete(tree, 9)
File "C:\Users\koopt_000\Desktop\College\Sophomore Semester 2\Computer Science 231\Chapter7\BinarySearchTree.py", line 111, in delete
ldepth == max(self.height(root.left))
TypeError: 'int' object is not iterable
Process finished with exit code 1
以下是从我的TreeNodes到BST（主要功能），然后是我的测试代码的以下代码部分。
class TreeNode(object):
def __init__(self, data = None, left=None, right=None):
self.item = data
self.left = left
self.right = right
def __str__(self):
return str(self.item)
from TreeNode import TreeNode
class BST(object):
#------------------------------------------------------------
def __init__(self):
"""create empty binary search tree
post: empty tree created"""
self.root = None
self.size = 0
def delete(self, root, item, ldepth = 0, rdepth = 0 ):
"""remove item from binary search tree
post: item is removed from the tree"""
if ldepth == 0:
ldepth == max(self.height(root.left))
if rdepth == 0:
rdepth == max(self.height(root.right))
if ldepth > rdepth:
depth = ldepth
print(depth)
elif ldepth < rdepth:
depth = rdepth
print(depth)
else:
depth = ldepth
print(depth)
self.root = self._subtreeDelete(root, item, depth)
#------------------------------------------------------------
def _subtreeDelete(self, root, item, depth):
if root is None: # Empty tree, nothing to do
return None
if item < root.item: # modify left
root.left = self._subtreeDelete(root.left, item)
elif item > root.item: # modify right
root.right = self._subtreeDelete(root.right, item)
else: # delete root
if root.left is None: # promote right subtree
root = root.right
elif root.right is None: # promote left subtree
root = root.left
else:
# root node can't be deleted, overwrite it with max of
# left subtree and delete max node from the subtree
root.item, root.left = self._subtreeDelMax(root.left)
return root
#------------------------------------------------------------
def _subtreeDelMax(self, root):
if root.right is None: # root is the max
return root.item, root.left # return max and promote left subtree
else:
# max is in right subtree, recursively find and delete it
maxVal, root.right = self._subtreeDelMax(root.right)
return maxVal, root
def height(self, root):
if root is None:
return 0
else:
return max(self.height(root.left), self.height(root.right)) + 1
from BinarySearchTree import BST
from TreeNode import TreeNode
tree = TreeNode(4, TreeNode(2, TreeNode(1), TreeNode(3)), TreeNode (7, TreeNode(6),TreeNode(9)))
a = BST()
a._subtreeInsert(tree, 10)
a._subtreeInsert(tree, 5)
a.delete(tree, 9)
print("PRE-ORDER TRANSVERSE:")
print(a.preOrder(tree))
print("IN-ORDER TRANSVERSE:")
print(a.inOrder(tree))
print("POST-ORDER TRANSVERSE:")
print(a.postOrder(tree))
print("The max depth of the tree is,", a.height(tree),"nodes deep.")
print("There are,", a.treeSize(tree),"nodes in this tree.")
有谁能告诉我什么错了？我需要这个才能使我的删除功能正常工作，
答案 0 :(得分：0)
python中的max（）函数接受一个可迭代的对象，就像一个列表，它可以在迭代中找到最大值。
self.height(root.left)
是一个单独的int，基本上是一个不可迭代的单值，这会引发你的错误。