title: Xpath Attribute REGEX
body: <p>Here is my code so far:</p>
  
  <pre><code>from lxml import html
  import requests
  
  page = requests.get('http://web.international.ucla.edu/institute/events')
  tree = html.fromstring(page.text)
  
  event_title = tree.xpath('//a[@href="/institute/event/&lt;&lt;&lt;REGEX&gt;&gt;&gt;"]/text()')
  
  print "Event Title: ", event_title
  </code></pre>
  
  <p>I'm scraping the page <a href="http://web.international.ucla.edu/institute/events" rel="nofollow">http://web.international.ucla.edu/institute/events</a> for event data, and I'd like to capture the titles. They are identified by 5-digit numbers. How can I do this?</p>