 <span class="n">step</span><span class="o">.</span><span class="n">lower</span><span class="p">()</span> <span class="ow">and</span> <span class="s1">&#39;by&#39;</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">step</span><span class="o">.</span><span class="n">lower</span><span class="p">():</span>
            <span class="n">my_error</span><span class="p">(</span><span class="n">step</span> <span class="o">+</span> <span class="s1">&#39;:</span><span class="se">\n</span><spa