">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">itemSets</span><span class="p">)):</span>
            <span class="n">itemI</span> <span class="o">=</span> <span class="n">itemSets</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
            <span class="k">if</span> <span class="n">itemI</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</s