Python program to insert a new node at the end of the Doubly Linked List
#Represent a node of doubly linked list
class Node:
def __init__(self,data):
self.data = data;
self.previous = None;
self.next = None;
class InsertEnd:
#Represent the head and tail of the doubly linked list
def __init__(self):
self.head = None;
self.tail = None;
#addAtEnd() will add a node to the end of the list
def addAtEnd(self, data):
#Create a new node
newNode = Node(data);
#If list is empty
if(self.head == None):
#Both head and tail will point to newNode
self.head = self.tail = newNode;
#head's previous will point to None
self.head.previous = None;
#tail's next will point to None, as it is the last node of the list
self.tail.next = None;
#Add newNode as new tail of the list
else:
#newNode will be added after tail such that tail's next will point to newNode
self.tail.next = newNode;
#newNode's previous will point to tail
newNode.previous = self.tail;
#newNode will become new tail
self.tail = newNode;
#As it is last node, tail's next will point to None
self.tail.next = None;
#display() will print out the nodes of the list
def display(self):
#Node current will point to head
current = self.head;
if(self.head == None):
print("List is empty");
return;
print("Adding a node to the end of the list: ");
while(current != None):
#Prints each node by incrementing pointer.
print(current.data),
current = current.next;
print();
dList = InsertEnd();
#Adding 1 to the list
dList.addAtEnd(1);
dList.display();
#Adding 2 to the list
dList.addAtEnd(2);
dList.display();
#Adding 3 to the list
dList.addAtEnd(3);
dList.display();
#Adding 4 to the list
dList.addAtEnd(4);
dList.display();
#Adding 5 to the list
dList.addAtEnd(5);
dList.display();
Output:
Adding a node to the end of the list:
1
Adding a node to the end of the list:
1 2
Adding a node to the end of the list:
1 2 3
Adding a node to the end of the list:
1 2 3 4
Adding a node to the end of the list:
1 2 3 4 5
