Singly linked list

singly-linked-list-in-python.py

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

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

    def display(self):
        currentNode = self.head
        while currentNode:
            print(currentNode.data)
            # quit()
            currentNode = currentNode.next
    def prepend(self,data):
        newNode = Node(data)
        newNode.next = self.head
        self.head = newNode

    def insertAfter(self, previousNode, data):
        if not previousNode:
            print('send prev node')
            return

        newNode = Node(data)
        newNode.next = previousNode.next
        previousNode.next = newNode

    def append(self, data):
        newNode = Node(data);
        if self.head is None:
            self.head = newNode
            return;
        lastNode = self.head
        while lastNode.next:
            lastNode = lastNode.next
        lastNode.next = newNode;


llist = LinkedList()
llist.append("A")
llist.append("B")
llist.append("C")
llist.prepend("D")
llist.insertAfter(llist.head.next,"E")
llist.display()