inserting item after another item linked list python
def insert_after_item(self, x, data):
n = self.start_node
print(n.ref)
while n is not None:
if n.item == x:
break
n = n.ref
if n is None:
print("item not in the list")
else:
new_node = Node(data)
new_node.ref = n.ref
n.ref = new_node