span> <span class="ow">in</span> <span class="nb">list</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">matrix</span><span class="p">[</span><span class="n">key</span><span class="p">]</span><span class="o">.</span><span class="n">items</span><span class="p">()):</span>
                <span class="k">if</span> <span class="n">value</span> <span class="o">&lt;</span> <span class="n">minsup</span><span class="p">:</span>
                    <span class="k">del