title: find 3 adjacent digits in a string
body: <p>Here is one solution to find all groups of 3 adjacent digits in a string:</p>
  
  <pre><code>m=re.findall(r"(?:\A|\s)\d\d\d(?:\s|$)", "111 chgsds 123 jdswu 456 x111101 765")
  </code></pre>
  
  <p>The output after calling findall:</p>
  
  <pre><code>['111 ', ' 123 ', ' 456 ', ' 765']
  </code></pre>
  
  <p>but I'm looking for a more elegant solution. Thanks.</p>