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">for</span> <span class="n">half_life</span> <span class="ow">in</span> <span class="n">hlf_dict</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;_ema_&quot;</span> <span class="o">+</span> <span class="n">half_life</span><span class="p">]</span>