一种非递归实现二叉树的中序遍历的方法

def inorder_traverse(root):
    stack = []; node = root
    while len(stack) > 0 or node is not None:
        while node is not None:
            stack.append(node)
            node = node.left
        node = stack.pop()
        visit(node) # 访问node节点，如输出node的value
        node = node.right