an class="n">c</span> <span class="ow">in</span> <span class="n">df</span><span
            class="o">.</span><span class="n">columns</span><span class="p">:</span>
                    <span class="k">if</span> <span class="n">c</span> <span class="o">!=</span> <span
            class="n">df</span><span class="o">.</span><span class="n">columns</span><span class="p">[</span><span
            class="o">-</span><span class="mi">1</span><span class="p">]:</span>
                        <span class="n">output</