</span><span class="p">)</span>

<span class="n">old_BILL_AMT</span> <span class="o">=</span> <span class="p">[</span><span class="s1">&#39;BILL_AMT3&#39;</span><span class="p">,</span> <span class="s1">&#39;BILL_AMT4&#39;</span><span class="p">,</span> <span class="s1">&#39;BILL_AMT5&#39;</span><span class="p">,</span> <span class="s1">&#39;BILL_AMT6&#39;</span><span class="p">]</span>
<span class="n">data</span><span class="p">[</span><span class="s1">&#39;BILL_AMT_old_mean&#39;</span><span class="p">]</s