如何在预订单遍历中打印AVLTree条目

class AVLNode:
    def __init__(self, key, value):
        self.key = key
        self.value = value
        self.left = None
        self.right = None
        self.height = 1

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

    def insert(self, key, value):
        self.root = self._insert(self.root, key, value)

    def _insert(self, node, key, value):
        if node is None:
            return AVLNode(key, value)
        
        if key < node.key:
            node.left = self._insert(node.left, key, value)
        else:
            node.right = self._insert(node.right, key, value)
        
        node.height = 1 + max(self._get_height(node.left), self._get_height(node.right))
        balance = self._get_balance(node)

        if balance > 1:
            if key < node.left.key:
                return self._rotate_right(node)
            else:
                node.left = self._rotate_left(node.left)
                return self._rotate_right(node)
        
        if balance < -1:
            if key > node.right.key:
                return self._rotate_left(node)
            else:
                node.right = self._rotate_right(node.right)
                return self._rotate_left(node)
        
        return node

    def _get_height(self, node):
        if node is None:
            return 0
        return node.height

    def _get_balance(self, node):
        if node is None:
            return 0
        return self._get_height(node.left) - self._get_height(node.right)

    def _rotate_left(self, z):
        y = z.right
        T2 = y.left

        y.left = z
        z.right = T2

        z.height = 1 + max(self._get_height(z.left), self._get_height(z.right))
        y.height = 1 + max(self._get_height(y.left), self._get_height(y.right))

        return y

    def _rotate_right(self, z):
        y = z.left
        T3 = y.right

        y.right = z
        z.left = T3

        z.height = 1 + max(self._get_height(z.left), self._get_height(z.right))
        y.height = 1 + max(self._get_height(y.left), self._get_height(y.right))

        return y

    def print_inorder(self):
        self._print_inorder(self.root)

    def _print_inorder(self, node):
        if node:
            self._print_inorder(node.left)
            print("Key:", node.key, "Value:", node.value)
            self._print_inorder(node.right)

# 创建AVL树并插入数据
tree = AVLTree()
tree.insert(5, "Value 5")
tree.insert(3, "Value 3")
tree.insert(7, "Value 7")
tree.insert(2, "Value 2")
tree.insert(4, "Value 4")
tree.insert(6, "Value 6")
tree.insert(8, "Value 8")

# 预订单遍历并打印AVL树条目
tree.print_inorder()