stackll py

# program to implement Linked List

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

    # returns true is LinkedList is Empty
    def isEmpty(self):
        if self.head is None:
            return True
        else:
            return False

    # method adds elements to the left of the Linked List
    def addToStart(self, data):
        # create a temporary node
        tempNode = Node(data)
        tempNode.setLink(self.head)
        self.head = tempNode
        del tempNode

    # method adds elements to the right of the Linked List
    def addToEnd(self, data):
        start = self.head
        tempNode = Node(data)
        while start.getNextNode():
            start = start.getNextNode()
        start.setLink(tempNode)
        del tempNode
        return True

    # method displays Linked List
    def display(self):
        start = self.head
        if start is None:
            print("Empty List!!!")
            return False

        while start:
            print(str(start.getData()))
            start = start.link
        print()

    # method pushes element to the Linked List
    def push(self, data):
        self.addToStart(data)
        return True

    # method removes and returns the last element from the Linked List
    def pop(self):
        if self.isEmpty():
            return False
        start = self.head
        data = start.getData()
        start = start.getNextNode()
        self.head = start

        return data

# node class
class Node:
    # default value of data and link is none if no data is passed
    def __init__(self, data=None, link=None):
        self.data = data
        self.link = link

    # method to update the data feild of Node
    def updateData(self, data):
        self.data = data

    # method to set Link feild the Node
    def setLink(self, node):
        self.link = node

    # method returns data feild of the Node
    def getData(self):
        return self.data

    # method returns address of the next Node
    def getNextNode(self):
        return self.link


# main method
# creating LinkedList
myList = LinkedList()

# adding some elements to the start of LinkedList
myList.push(1)
myList.push(2)
myList.push(3)
myList.push(4)
myList.push(5)
myList.push(6)

print("The Contents of the stack are : ")
myList.display()

# adding some elements to the End of the LinkedList
print("Removing 3 elements from the stack\n")
myList.pop()
myList.pop()
myList.pop()

print("The Contents of the stack are : ")
myList.display()