701. Insert into a Binary Search Tree

class Solution:
    def insertIntoBST(self, root: TreeNode, val: int) -> TreeNode:
        temp = TreeNode(val)
        if root is None:
            root = temp
        if val < root.val:
            if root.left is None:
                root.left = temp
            else:
                root.left = self.insertIntoBST(root.left, val)
        elif val > root.val:
            if root.right is None:
                root.right = temp
            else:
                root.right = self.insertIntoBST(root.right, val)
        return root