#binary tree implementation
class node(object):
def __init__(self, head, left=None, right=None):
self.head = head
self.left = left
self.right = right
def left_branch(lst):
bt = node(lst.pop())
current = bt
while lst != []:
current.left = node(lst.pop())
current = current.left
return bt
def append_right(bt, val, branch):
current = bt
while current != None:
if current.head == branch:
current.right = val
else:
current = current.left
raise ValueError("branch not found")