A doubly linked list contains a chain of nodes similar to a regular linked list except each node contains both a pointer to the next node in the chain and a pointer to the previous node in the chain.

Example implementation of a Node class:

class Node:
    def __init__(self, value, next = None):
        self.value = value
        self.next = next                              # pointer to next node 
        self.prev = next                           # new pointer to the previous node 

The following example is a Doubly Linked List class that creates a single head node:

class DoublyLList:
    def __init__(self):
        self.head = None

The following snippet creates a doubly linked list with 3 elements:

my_doubly_llist = DoublyLList()                   # creates a Doubly LinkedList object
my_doubly_llist.head = Node("Hello")         # sets the head's value to "Hello"
element2 = Node("Good")                    # creates a Node with value "Good"
element3 = Node("Morning")                     # creates a Node with value "Morning"
my_doubly_llist.head.next = element2     # sets the head's next element to element2
element2.next = element3                    # sets element2's next element to element3
element2.prev = my_doubly_llist.head        # sets element2's prev element to head
element3.prev = element2             # sets element3's prev element to element2