an class="bp">self</span><span class="o">.</span><span class="n">value</span> <span class="o">=</span> <span class="n">value</span>

</div>
  <span class="k">def</span> <span class="nf">__getitem__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span><span class="n">i</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;Obtain item from value atttribute.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="bp">sel