When it is required to create and display the elements in a doubly linked list, a ‘Node’ class needs to be created. In this class, there are three attributes, the data that is present in the node, the access to the next node of the linked list, and the access to the previous node of the linked list.
Below is a demonstration for the same −
Example
class Node:
def __init__(self, my_data):
self.prev = None
self.data = my_data
self.next = None
class double_list:
def __init__(self):
self.head = None
self.tail = None
def add_data(self, my_data):
new_node = Node(my_data)
if(self.head == None):
self.head = self.tail = new_node;
self.head.previous = None;
self.tail.next = None;
else:
self.tail.next = new_node;
new_node.previous = self.tail;
self.tail = new_node;
self.tail.next = None;
def print_it(self):
curr = self.head
if (self.head == None):
print("The list is empty")
return
print("The nodes in the doubly linked list are :")
while curr != None:
print(curr.data)
curr = curr.next
my_instance = double_list()
print("Elements are being added to the doubly linked list")
my_instance.add_data(10)
my_instance.add_data(24)
my_instance.add_data(54)
my_instance.add_data(77)
my_instance.add_data(92)
my_instance.print_it()Output
Elements are being added to the doubly linked list The nodes in the doubly linked list are : 10 24 54 77 92
Explanation
- The ‘Node’ class is created.
- Another class with required attributes is created.
- A method named ‘add_data’ is defined, that is used to add data to the doubly linked list.
- Another method named ‘print_it’ is defined, that displays the nodes of the circular linked list.
- An object of the ‘double_list’ class is created, and the methods are called on it to display the nodes of the doubly linked list.
- An ‘init’ method is defined, that the root, head, and tail nodes of the doubly linked list to None.
- These methods are called, and data is added to the list.
- This is displayed on the console using the ‘print_it’ method.