n class="k">else</span><span class="p">:</span>
                    <span class="n">descriptors</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">i_des</span><span class="p">)</span>

                <span class="k">if</span> <span class="n">derivatives_shape</span><span class="p">:</span>
                    <span class="k">if</span> <span class="n">is_sparse</span><span class="p">:</span>
                        <span class="n">sample_index</span> <span cla