Help me understand Inorder Traversal without using recursion

Question

I am able to understand preorder traversal without using recursion, but I\'m having a hard time with inorder traversal. I just don\'t seem to get it, perhaps, because I have

Answer 1

class Tree:

    def __init__(self, value):
        self.left = None
        self.right = None
        self.value = value

    def insert(self,root,node):
        if root is None:
            root = node
        else:
            if root.value < node.value:
                if root.right is None:
                    root.right = node
                else:
                    self.insert(root.right, node)
            else:
                if root.left is None:
                    root.left = node
                else:
                    self.insert(root.left, node)       

    def inorder(self,tree):
        if tree.left != None:
            self.inorder(tree.left)
        print "value:",tree.value

        if tree.right !=None:
            self.inorder(tree.right)

    def inorderwithoutRecursion(self,tree):
        holdRoot=tree
        temp=holdRoot
        stack=[]
        while temp!=None:
            if temp.left!=None:
                stack.append(temp)
                temp=temp.left
                print "node:left",temp.value

            else:
                if len(stack)>0:
                    temp=stack.pop();
                    temp=temp.right
                    print "node:right",temp.value

Answer 2

Little Optimization of answer by @Emadpres

def in_order_search(node):
    stack = Stack()
    current = node

    while True:
        while current is not None:
            stack.push(current)
            current = current.l_child

        if stack.size() == 0:
            break

        current = stack.pop()
        print(current.data)
        current = current.r_child