Tree traversal - Inorder iterative implementation

inorder_traversal_iterating.py

def inorder_traversal_iterating(root):
    result = []
    # using stack
    stack = []
    current = root
    while stack or current:
        if current:
            # traverse the left subtree
            stack.append(current)
            current = current.left
            continue
        # visit node
        current = stack.pop()
        result.append(current.val)
        # traverse the right subtree
        current = current.right
    return result