=</span> <span class="n">ts</span><span class="p">[:</span><span class="nb">len</span><span class="p">(</span><span class="n">ts</span><span class="p">)</span><span class="o">-</span><span class="n">tau</span><span class="p">]</span>
        <span class="n">ts_o</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">Series</span><span class="p">(</span><span class="n">ts_o</span><span class="p">)</span>
        <span class="n">ts_d</span> <span class="o">=</span> <s