def add(self, new_data):
temp = Node(new_data)
if self.is_empty():
self.tail = temp
temp.set_next(self.head)
self.head = temp
self.size +=1
def append(self, d):
if self.is_empty():
self.add(d)
else:
temp = Node(d)
temp.set_next(None)
self.tail.set_next(temp)
self.tail = temp
self.size +=1
