Python Data Structures and Algorithms

Append operation

The first operation that we need to perform is to append items to the list. This operation is sometimes called an insert operation. Here we get a chance to hide away the Node class. The user of our list class should really never have to interact with Node objects. These are purely for internal use.

A first shot at an append() method may look like this:

    class SinglyLinkedList:         # ...         def append(self, data):             # Encapsulate the data in a Node             node = Node(data)             if self.tail == None:                 self.tail = node             else:                 current = self.tail                 while current.next:                     current = current.next                 current.next = node 

We encapsulate data in a node, so that it now has the next pointer attribute. From here we check if there are any existing nodes in the list ...