<p dir="auto">Enhance <a href="https://github.com/pandas-dev/pandas/blob/master/doc/source/contributing.rst">https://github.com/pandas-dev/pandas/blob/master/doc/source/contributing.rst</a> with a discussion of how our <code class="notranslate">_shared_docs</code> system works.</p>
<ul dir="auto">
<li>Why we do it (reduce duplicate docstrings, while still having some class-specific stuff)</li>
<li>How it's done (Appender, _shared_docs dict, _shared_doc_kwargs)</li>
<li>How to substitute values</li>
</ul>
<p dir="auto">The output from .groups on a grouped DataFrame should be handled similarly to a large DataFrame, where beyond a certain length, the data is displayed in a summary form rather than output in its entirety.</p>
<p dir="auto">This truncation should occur both at the group level (large number of groups) and per-group (large amount of data points in a group).</p>