title: Convert list of lists of bs4.element.ResultsSets into a list of strings
body: <p>As I am working on scraping a website, I have found myself with a list of lists containing bs4.element.ResulstSets from a find_all() search. Therefore the output of my variable (features) looks like this</p>
  <pre><code>[[&lt;li class=&quot;WlSsj&quot;&gt;Terrasse&lt;/li&gt;],
  [&lt;li class=&quot;WlSsj&quot;&gt;Balkon&lt;/li&gt;, &lt;li class=&quot;WlSsj&quot;&gt;Video Live-Besichtigung&lt;/li&gt;],
  [&lt;li class=&quot;WlSsj&quot;&gt;Balkon&lt;/li&gt;, &lt;li class=&quot;WlSsj&quot;&gt;Terrasse&lt;/li&gt;],
  [],
  [&lt;li class=&quot;WlSsj y7k9g&quot;&gt;Neubauprojekt&lt;/li&gt;, &lt;li class=&quot;WlSsj&quot;&gt;Garten&lt;/li&gt;, &lt;li class=&quot;WlSsj&quot;&gt;Balkon&lt;/li&gt;, &lt;li class=&quot;WlSsj&quot;&gt;Terrasse&lt;/li&gt;]]
  </code></pre>
  <p>I would now like to turn this into a list of strings like this:</p>
  <pre><code>[&quot;Terrasse&quot;,
  &quot;Balkin, Video-Besichtigung&quot;,
  &quot;Balkon, Terrasse&quot;,
  &quot;&quot;,
  &quot;Neubauprojekt, Garten, Balkon, Terrasse&quot;]
  </code></pre>
  <p>I have tried many things but sometimes the empty list is not converted to an empty string or the order is not consistent.
  Thank you very much in advance.</p>