ml"><a href="wrangling-data-frames.html#ordering-data-frames"><i class="fa fa-check"></i><b>3.4.3</b> Ordering data frames</a></li>
<li class="chapter" data-level="3.4.4" data-path="wrangling-data-frames.html"><a href="wrangling-data-frames.html#adding-columns-and-rows"><i class="fa fa-check"></i><b>3.4.4</b> Adding columns and rows</a></li>
<li class="chapter" data-level="3.4.5" data-path="wrangling-data-frames.html"><a href="wrangling-data-frames.html#merging-data-frames"><i class="fa fa-check"></i><b>3.4