SyntaxError: multiple exception types must be parenthesized #34

I am getting this error right after I execute the script, here's the try except that generates the error:
try:
logger.info("Crawling %s" % url)
request = urllib2.urlopen(req)
except urllib2.URLError, e:
logger.error("Exception at url: %s\n%s" % (url, e))
any idea what might be wrong? Thanks.