#!/usr/bin/env python# -*- coding: utf-8 -*-# learn <<Problem Solving with Algorithms and Data Structures>># Release 3.0# chengang882 @ 2016-12-21# Completed implementation of a Unordered List ADTclass Node(object):    def __init__(self, init_data):        self.data = http://www.mamicode.com/init_data"__main__":    ul = UnorderedList()    print(ul.is_empty())    ul.add(45)    ul.add(78)    ul.add("adfd")    ul.add("4345")    ul.add(3)    print(ul.is_empty())    print(ul.size())    print(ul.search(45))    print(ul.remove(78))    print(ul)

>>> TrueFalse5TrueNone<__main__.UnorderedList object at 0x0000000002F1C860>>>>