">group_iter</span> <span class="o">=</span> <span class="nb">iter</span><span class="p">(</span><span class="n">mark_groups</span><span class="p">)</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="c1"># False</span>
                <span class="n">group_iter</span> <span class="o">=</span> <span class="nb">iter</span><span class="p">({}</span><span class="o">.</span><span class="n">items</span><span class="p">())</span>

            <span class="k">if</spa