When it is required to create a doubly linked list and display the elements in a reversed order, 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.
Another class needs to be created that would have an initialization function, and the head of the node would be initialized to ‘None’ inside this.
Multiple methods are defined by the user to add node to the linked list, to reverse the nodes and print the nodes in the linked list.
Below is a demonstration for the same −
class Node: def __init__(self, my_data): self.prev = None self.data = my_data self.next = None class reverse_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 reverse_vals(self): curr = self.head; while(curr != None): temp = curr.next curr.next = curr.previous curr.previous = temp curr = curr.previous temp = self.head self.head = self.tail self.tail = temp def print_it(self): curr = self.head if (self.head == None): print("The list is empty") return print("The nodes are :") while curr != None: print(curr.data) curr = curr.next my_instance = reverse_list() print("Elements are being added to the list") my_instance.add_data(10) my_instance.add_data(14) my_instance.add_data(24) my_instance.add_data(17) my_instance.add_data(22) my_instance.print_it() print("The reversed nodes in the doubly linked list are : ") my_instance.reverse_vals() my_instance.print_it()
Elements are being added to the list The nodes are : 10 14 24 17 22 The reversed nodes in the doubly linked list are : The nodes are : 22 17 24 14 10