s="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">nodes</span><span class="p">):</span>
            <span class="k">for</span> <span class="n">j</span><span class="p">,</span> <span class="n">node_j</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">nodes</span><span class="p">):</span>
                <span class="k">if</span> <span class="n">i</span> <span class="o">==</span> <span class="n">j</span><span class