Python实现栈

#!usr/bin/env python  
#-*- coding:utf-8 -*- 
 
""" 
@author:yzk13 
@time: 2018/04/19
栈
"""
 
class Stack(object):
    """
    栈
    """
    def __init__(self):
        """
        初始化
        """
        self.items = []
 
    def is_empty(self):
        """
        栈是否为空
        :return:
        """
        return self.items == []
 
    def peek(self):
        """
        返回栈顶元素
        :return:
        """
        return self.items[-1]
 
    def size(self):
        """
        返回栈的大小
        :return:
        """
        return len(self.items)
 
    def push(self, item):
        """
        进栈
        :return:
        """
        self.items.append(item)
 
    def pop(self):
        """
        删除栈最顶层的元素，并返回这个元素  出栈
        :return:
        """
        return self.items.pop()
 
    def print(self):
        """
        打印
        :return:
        """
        print(self.items)
 
    def sort(self):
        """
        排序
        :return:
        """
        self.items.sort()
 
if __name__ == '__main__':
    s = Stack()
    # 入栈
    s.push(3)
    s.push(-2)
    s.push(7)
    s.push(6)
    s.push(1)
    s.print()
 
    # 测试大小
    print('栈大小为: ', s.size())
 
    # 出栈
    print('出栈元素为: ', s.pop())
    s.print()
 
    # 获取栈顶
    print('栈顶为: ', s.peek())
 
    # 测试排序
    s.sort()
 
    s.print()