title: Regular expression to filter list of strings matching a pattern
body: <p>I use R a lot more and it is easier for me to do it in R:</p>
  <pre><code>&gt; test &lt;- c('bbb', 'ccc', 'axx', 'xzz', 'xaa')
  &gt; test[grepl(&quot;^x&quot;,test)]
  [1] &quot;xzz&quot; &quot;xaa&quot;
  </code></pre>
  <p>But how to do it in python if <code>test</code> is a list?</p>
  <p>P.S. I am learning python using google's python exercise and I prefer using regular expression.</p>