Stack

A stack is a linear data structure that follows the Last In, First Out (LIFO) principle. It allows for adding and removing elements in a specific order, where the last element added is the first one to be removed.

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class Stack:
    def __init__(self):
        self.__items = []

    def __str__(self):
        return str(self.__items)

    @property
    def size(self):
        return len(self.__items)

    def is_empty(self):
        return len(self.__items) == 0

    def push(self, item):
        self.__items.append(item)

    def pop(self):
        if self.is_empty():
            raise IndexError("Stack is empty")
        return self.__items.pop()

    def peek(self):
        if self.is_empty():
            raise IndexError("Stack is empty")
        return self.__items[self.size() - 1]