title: Python domain name list regex
body: <p>I wish to get all the the domain names in the given string using python. 
  i have tried the below but i am not getting the o/p as expected</p>
  
  <pre><code>str = "ctcO6OgnWRAxLtu+akRCFwM asu.edu zOiV6Wo6nDnUhQkZO4XTySrTRwLMgozM9R/LyQs2r+Pb tarantino.cs.ucsb.edu,128.111.48.123 ssh-rsa 9SMF4U+qJW03Bh1"
  list = re.findall(r'([a-zA-Z0-9]+(-[a-zA-Z0-9]+)*\.)+[a-z]{2,10}', str)
  print list
  </code></pre>
  
  <p>I want the output as:</p>
  
  <pre><code>asu.edu , tarantino.cs.ucsb.edu  
  </code></pre>
  
  <p>but what I get is:</p>
  
  <pre><code>[('asu.', ''), ('ucsb.', '')]
  </code></pre>
  
  <p>What am I missing ?</p>