python2 处理urllib/urllib2错误并打印源码

import urllib2
import urllib
url = 'http://localhost/12.php'
data = {}
data['cmd']='whoami'
data = urllib.urlencode(data)
try:
    content = urllib2.urlopen(url, data)
    print content.read()
except urllib2.HTTPError,E:
    print 'httperror'
    print E.read()
except urllib2.URLError,e:
    print 'urlerror'
    print e.reason