Python Program For Deleting A Node In A Doubly Linked List

# Program to delete a node in a 
# doubly-linked list

# For Garbage collection
import gc

# A node of the doubly linked list
class Node:
    
    # Constructor to create a new node
    def __init__(self, data):
        self.data = data 
        self.next = None
        self.prev = None

class DoublyLinkedList:

     # Constructor for empty Doubly 
     # Linked List
    def __init__(self):
        self.head = None
 
   # Function to delete a node in a Doubly 
   # Linked List. head_ref --> pointer to 
   # head node pointer. dele --> pointer to 
   # node to be deleted.
    def deleteNode(self, dele):
        
        # Base Case
        if self.head is None or dele is None:
            return 
        
        # If node to be deleted is head node
        if self.head == dele:
            self.head = dele.next

        # Change next only if node to be 
        # deleted is NOT the last node
        if dele.next is not None:
            dele.next.prev = dele.prev
    
        # Change prev only if node to be 
        # deleted is NOT the first node
        if dele.prev is not None:
            dele.prev.next = dele.next

        # Finally, free the memory occupied 
        # by dele
        # Call python garbage collector
        gc.collect()


    # Given a reference to the head of a 
    # list and an integer, inserts a new 
    # node on the front of list
    def push(self, new_data):
 
        # 1. Allocates node
        # 2. Put the data in it
        new_node = Node(new_data)
 
        # 3. Make next of new node as head 
        # and previous as None (already None)
        new_node.next = self.head
 
        # 4. Change prev of head node to 
        # new_node
        if self.head is not None:
            self.head.prev = new_node
 
        # 5. Move the head to point to the 
        # new node
        self.head = new_node

    def printList(self, node):
        while(node is not None):
            print node.data,
            node = node.next

# Driver code

# Start with empty list
dll = DoublyLinkedList()

# Let us create the doubly linked list 
# 10<->8<->4<->2
dll.push(2);
dll.push(4);
dll.push(8);
dll.push(10);

print "Original Linked List",
dll.printList(dll.head)

# Delete nodes from doubly linked list
dll.deleteNode(dll.head)
dll.deleteNode(dll.head.next)
dll.deleteNode(dll.head.next)

# Modified linked list will be NULL<-8->NULL
print "Modified Linked List",
dll.printList(dll.head)
# This code is contributed by Nikhil Kumar Singh(nickzuck_007)