#!/usr/local/bin/python2
#coding:utf-8
import collections

class q(collections.MutableSequence):
    def __init__(self, *items):
        self._items = list(items)
        self._compiled_items = list(items)

    def __repr__(self):
        return '{}({})'.format(self.__class__.__name__)

    def __getitem__(self, index):
        return self._items[index]

    def __setitem__(self, index, value):
        self._items[index] = value
        self._compiled_items[index] = value
  
    def __delitem__(self, index):
        del self._items[index], self._compiled_items[index]
        
    def __len__(self):
        return len(self._items)
        
    def insert(self, index, value):
        self._items.insert(index, value)
        self._compiled_items.insert(index, value)

l = q(1,2,3)
l.extend((4,5,6))
l[1] = 'あ'
print l, l._compiled_items