Python-сообщество

class Sequence(object):
    def __init__(self):
        self.first = None
        self.len = 0
       
    def add(self,new):
        self.len += 1
        if self.first is None:
            self.first = element(new)
        else:
            self.first = element(new, self.first)
     
    def find(self, index):
        i = self.first
        num = 0
        while num is not index:
            i = i.nex
            num += 1
        print i.value

class element(object):
    def __init__(self, value = None, nex = None):
        self.value = value
        self.nex = nex

from list import Sequence as s
import unittest
class testsequence (unittest.TestCase):
   
    def setUp(self):
        self.lst = s()
    
    def testadd(self):
        self.lst.add(1)
        self.lst.add(2)
        self.lst.add(3)
        self.lst.add(4)
        self.lst.printall()
        
            
    def testfind(self):
        index = input ("Введите индекс")
        self.lst.find(index)
      
if __name__ == "__main__":
    unittest.main()