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


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