class TreeNode: def __init__(self, data): self.data = data self.left = None self.right = None def preOrderTraversal(node): if node is None: return print(node.data, end=", ") preOrderTraversal(node.left) preOrderTraversal(node.right) root = TreeNode('R') nodeA = TreeNode('A') nodeB = TreeNode('B') nodeC = TreeNode('C') nodeD = TreeNode('D') nodeE = TreeNode('E') nodeF = TreeNode('F') nodeG = TreeNode('G') root.left = nodeA root.right = nodeB nodeA.left = nodeC nodeA.right = nodeD nodeB.left = nodeE nodeB.right = nodeF nodeF.left = nodeG # Traverse preOrderTraversal(root)