def addTail(self, v):
print("adding value", v, " at the end of the list")
cell = Cell()
cell.value = v
cell.next = None
if self.tail == None:
cell.previous = None
self.head = cell
self.tail = cell
else:
cell.previous = self.tail
self.tail.next = cell
self.tail = cell
self.dump()
def addHead(self, value):
print("adding value", value, " at the head of the list")
cell = Cell()
cell.value = value
cell.previous = None
if self.head == None:
cell.next = None
self.head = cell
self.tail = cell
else:
cell.next = self.head
self.head.previous = cell
self.head = cell
self.dump()
