s="sd">        &gt;&gt;&gt; f = qc.read_csv(&quot;lineitem.csv&quot;)</span>

<span class="sd">        Drop the l_orderdate and l_orderkey columns</span>

<span class="sd">        &gt;&gt;&gt; f = f.drop([&quot;l_orderdate&quot;, &quot;l_orderkey&quot;])</span>

<span class="sd">        This will now fail, since you dropped l_orderdate</span>

<span class="sd">        &gt;&gt;&gt; f = f.select([&quot;l_orderdate&quot;])</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">assert</span> 