"bp">self</span><span class="o">.</span><span class="n">species</span><span class="p">[</span><span class="n">n</span><span class="p">])</span> <span class="o">==</span> <span class="s2">&quot;C&quot;</span><span class="p">]</span>

        <span class="c1"># Condition one: double/triple bonds to heteroatoms</span>
        <span class="k">for</span> <span class="n">node</span> <span class="ow">in</span> <span class="n">carbons</span><span class="p">:</span>
            <span class="n">neighbors</span> <span