Python插入结点函数

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

    def insert_node(self, data):
        new_node = Node(data)
        if self.head is None:
            self.head = new_node
        else:
            current = self.head
            while current.next:
                current = current.next
            current.next = new_node

class Node:
    def __init__(self, key):
        self.key = key
        self.left = None
        self.right = None

def insert_node(root, key):
    if root is None:
        return Node(key)
    if key < root.key:
        root.left = insert_node(root.left, key)
    else:
        root.right = insert_node(root.right, key)
    return root