Implementar una función no recursiva para recorrer un árbol binario en inorden. tiene que contener un ejemplo de aplicacion

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

def inorder(root):
  if root is not None:
    inorder(root.left)
    print (root.data)
    inorder(root.right)

def inorder_no_rec(root):
  if root is None:
    return []
  stack = []
  res = []
  current = root
  while True:
    if current is not None:
      stack.append(current)
      current = current.left
    elif stack:
      current = stack.pop()
      res.append(current.data)
      current = current.right
    else:
      break
  return res

root = Node(1)
root.left = Node(2)
root.right = Node(3)
root.left.left = Node(4)
root.left.right = Node(5)
root.right.left = Node(6)
root.right.