def insert_at_tail(self, data):
node = Node(data)
curr = self.head
while curr.next:
curr = curr.next
curr.next = node
node.prev = curr
def insert_after(self, locdata, data):
node = Node(data)
curr = self.head
while curr.data != locdata and curr.next:
curr = curr.next
node.prev = curr
node.next = curr.next
node.next.prev = node
curr.next = node
def insert_at_pos(self, pos, data):
node = Node(data)
curr = self.head
count = 1
while count != pos and curr.next:
curr = curr.next
count += 1
node.prev = curr
node.next = curr.next
node.next.prev = node
curr.next = node
