代码如下：

#coding:gbk
import urllib2,urllib,cookielib,re

\'\'\'
 通用的登陆DZ论坛
 参数说明parms:
   username:用户名(必填),
   password :密码(必填),
   domain:网站域名，注意格式必须是：http://www.xxx.xx/(必填),
   answer:问题答案,
   questionid:问题ID,
   referer:跳转地址
   
 这里使用了可变关键字参数(相关信息可参考手册)
\'\'\'
def login_dz(**parms):

  #初始化
  parms_key = [\'domain\',\'answer\',\'password\',\'questionid\',\'referer\',\'username\']
  arg = {}
  for key in parms_key:
    if key in parms:
      arg[key] = parms[key]
    else:
      arg[key] = \'\'
      
  #cookie设置
  cookieFile = \'./kan_cookies.dat\'
  cookie = cookielib.LWPCookieJar()
  opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookie))

  #获取formhash
  pre_login = arg[\'domain\']+\'member.php?mod=logging&action=login&infloat=yes&handlekey=login&inajax=1&ajaxtarget=fwin_content_login\'
  c = opener.open(pre_login).read()
  cookie.save(cookieFile)
  patt = re.compile(r\'.*?name=\"formhash\".*?value=\"(.*?)\".*?\')
  formhash = patt.search(c)
  if not formhash:
    raise Exception(\'GET formhash Fail!\')
  formhash = formhash.group(1)

  #登陆
  postdata = {
   \'answer\':arg[\'answer\'],
   \'formhash\':formhash,
   \'password\':arg[\'password\'],
   \'questionid\':0 if arg[\'questionid\']==\'\' else arg[\'questionid\'],
   \'referer\':arg[\'domain\'] if arg[\'referer\']==\'\' else arg[\'referer\'],
   \'username\':arg[\'username\'],
    }

  postdata = urllib.urlencode(postdata)
  req = urllib2.Request(
    url= arg[\'domain\']+\'member.php?mod=logging&action=login&loginsubmit=yes&handlekey=login&loginhash=LCaB3&inajax=1\',
    data=postdata
    )
  c = opener.open(req).read(300)
  flag = \'登陆失败 %s\'%arg[\'username\']
  if \'succeedhandle_login\' in c:
    flag = True
  return flag


#使用例子：基本参数登陆
user=\'xxx\'
pwd=\'xxx\'
dom=\'http://www.discuz.net/\' #另一个测试网站：http://bbs.jb51.net/
try:
  flag = login_dz(username=user,password=pwd,domain=dom)
  print(flag)
except Exception,e:
  print(\'Error:\',e)