pan class="k">if</span> <span class="nb">tuple</span><span class="p">([</span><span class="n">item</span><span class="p">])</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">items</span><span class="p">:</span>
                    <span class="n">items</span><span class="p">[</span><span class="nb">tuple</span><span class="p">([</span><span class="n">item</span><span class="p">])]</span> <span class="o">=</span> <span class="nb">set</span><span class="p">()</span>
               