code: def grab_definition(self, url):
          
          re_description = re.compile('Description:(.+?\\n)')
          re_table_name = re.compile("(\w+ Table.+)")
          if url.startswith('//'):
              url = 'http:' + url
          elif url.startswith('/'):
              url = 'http://www.epa.gov' + url
          try:
              html = urlopen(url).read()
              doc = lh.fromstring(html)
              main = doc.cssselect('#main')[0]
              text = main.text_content()
              definition = re_description.search(text).group(1).strip()
          except (AttributeError, IndexError, TypeError, HTTPError):
              print url
          else:
              value = re_table_name.sub('', definition)
              return value
          return url
docs: Grab the column definition of a table from the EPA using a combination
          of regular expressions and lxml.