StackLinkedList.py

#   Created by Elshad Karimov on 23/05/2020.
#   Copyright © 2020 AppMillers. All rights reserved.

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

class LinkedList:
    def __init__(self):
        self.head = None
    
    def __iter__(self):
        curNode = self.head
        while curNode:
            yield curNode
            curNode = curNode.next

class Stack:
    def __init__(self):
        self.LinkedList = LinkedList()
    
    def __str__(self):
        values = [str(x.value) for x in self.LinkedList]
        return '\n'.join(values)
    
    def isEmpty(self):
        if self.LinkedList.head == None:
            return True
        else:
            return False

    def push(self, value):
        node = Node(value)
        node.next = self.LinkedList.head
        self.LinkedList.head = node
    
    def pop(self):
        if self.isEmpty():
            return "There is not any element in the stack"
        else:
            nodeValue = self.LinkedList.head.value
            self.LinkedList.head = self.LinkedList.head.next
            return nodeValue
    
    def peek(self):
        if self.isEmpty():
            return "There is not any element in the stack"
        else:
            nodeValue = self.LinkedList.head.value
            return nodeValue
    
    def delete(self):
        self.LinkedList.head = None
    



customStack = Stack()
customStack.push(1)
customStack.push(2)
customStack.push(3)

print(customStack.peek())