ess is almost the same as that in
<code>dplyr</code>:</p>
<div class="sourceCode" id="cb7"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="fu"><a href="../reference/select.html">select_dt</a></span><span class="op">(</span><span class="va">flights</span>, tail_num <span class="op">=</span> <span class="va">tailnum</span><span class="op">)</span></span>
<span><span class="fu"><a href="../reference/rename_dt.html">rename_dt</a></span><span class="op">(</span><span class="va">f