><span class="p">,</span> <span class="n">half_life</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">hlf_dict</span><span class="p">):</span>
        <span class="k">if</span> <span class="n">i</span> <span class="o">&lt;</span> <span class="mi">3</span><span class="p">:</span>
            <span class="n">df</span><span class="p">[</span><span class="n">col</span> <span class="o">+</span> <span class="s2">&quot;_roll_vol_&quot;</span> <span class="o"