python实现简单栈

# -*- coding: utf-8 -*-


class Stack(object):
    """栈"""
    def __init__(self):
        self.__list = []

    def push(self, item):
        """添加一个新元素item到站定"""
        self.__list.append(item)

    @property
    def pop(self):
        """弹出栈顶元素"""
        return self.__list.pop()

    @property
    def peek(self):
        """返回栈顶元素"""
        if self.__list:
            return self.__list[-1]

    @property
    def is_empty(self):
        """判断是否为空"""
        return not self.__list

    @property
    def size(self):
        """返回栈的元素个数"""
        return len(self.__list)


if __name__ == '__main__':
    s = Stack()
    print(s.is_empty)
    s.push(1)
    s.push(2)
    s.push(3)
    s.push(4)
    s.push(5)
    print(s.is_empty)
    print(s.size)
    print(s.peek)
    print(s.pop)
    print(s.pop)
    print(s.pop)
    print(s.pop)
    print(s.pop)
    print(s.peek)
    print(s.size)
    print(s.is_empty)