title: Handle several adjacent regex matches
body: <p>Having a regex pattern which can be found several times in a text, how would one chooses and differs between the matches in this case?</p>
  
  <ul>
  <li>choose the first match.</li>
  <li>ignore the peripherals.</li>
  <li>only one match using index.</li>
  </ul>
  
  <hr>
  
  <p><strong>Example:</strong></p>
  
  <pre class="lang-py prettyprint-override"><code>
  regex_pattern = r"(AB.+?AbB)|(CD.+?CdD)|(EF.+?EfF)"
  
  text = "for finding several CDadjacent CDtagsCdDCdD in a 
          text this is an ABexampleAbB text"
  </code></pre>
  
  <p>the first match is <strong>CDadjacent CDtagsCdD</strong>.<br>
  while one might wants to match both:<br>
  <strong>CD</strong>adjacent <strong>CD</strong>tags<strong>CdDCdD</strong><br>
  and. . . . . . . <strong>CD</strong>tags<strong>CdD</strong></p>