title: Regular expression to match one from two groups
body: <p>I want to perform operation like select any one suitable group from two 
  for e.g:</p>
  
  <pre><code>gmail.com|gmail.co.in 
  </code></pre>
  
  <p>this gives me direct result but how can I write regular expression for python to map email id for above case.
  Note. I just want to map 3 char after dot or max two group of dot and 2 character</p>
  
  <p>I tried writing regex as :</p>
  
  <pre><code>[\w]+\.?[\w]{3}|[[\w]{2}\.?]{2}
  </code></pre>
  
  <p>but wont give me expected results</p>
  
  <p>If tried to use () returns group for e.g:<code>abcd@gmail.com</code> will return <code>gmail.com</code> but need to retrieve whole email address.</p>