span class="p">:</span>
            <span class="n">tree_edge_2_node</span><span class="p">[(</span><span class="n">n</span><span
            class="p">[</span><span class="mi">1</span><span class="p">],</span> <span class="n">n</span><span
            class="p">[</span><span class="mi">0</span><span class="p">])]</span><span class="o">.</span><span
            class="n">append</span><span class="p">(</span><span class="n">node</span><span class="p">)</span>
        <span class="k">else</span><span class="p