index_path</span> <span class="o">=</span> <span class="sa">f</span><span class="s1">'</span><span class="si">{</span><span class="n">shuffle_index_directory</span><span class="si">}</span><span class="s1">/.index/</span><span class="si">{</span><span class="n">search_class</span><span class="si">}</span><span class="s1">.txt'</span>

    <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">white_list_formats</span><span class="p">,</span> <span class="nb">list