Doubly linked list Insertion at given position Python

PROGRAM TO INSERT A NODE TO A DOUBLY LINKED LIST AFTER A GIVEN NODE

def insertAfter(self, prev_node, new_data):

 

        # 1. check if the given prev_node is NULL

        if prev_node is None:

            print("This node doesn't exist in DLL")

            return

 

        #2. allocate node  & 3. put in the data

        new_node = Node(data = new_data)

 

        # 4. Make next of new node as next of prev_node

        new_node.next = prev_node.next

 

        # 5. Make the next of prev_node as new_node

        prev_node.next = new_node

 

        # 6. Make prev_node as previous of new_node

        new_node.prev = prev_node

 

        # 7. Change previous of new_node's next node */

        if new_node.next is not None:

            new_node.next.prev = new_node

CREDITS: https://www.geeksforgeeks.org/doubly-linked-list/