再次求教一个问题~关于验证码图片下载的

目标：实现批量注册tom邮箱
已做：在python里用某api给予图片可以返回text，
问题：如何下载验证码图片
这是目前写的程序，就差
import re;
import cookielib;
import urllib;
import urllib2;
def emulateLoginTom():
cj = cookielib.CookieJar();
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj));
urllib2.install_opener(opener);
print " emulate login tom";
MainLoginUrl = http://bjcgi.tom.com/cgi-bin/tom_reg.cgi?rf=060704;
#######
postDict = {
'funcid'="reguser",
'rf'="060704",
'refer'=,
'year'="1980",
'month'="1",
'day'="1",
'argee'="1",
'idnum'="4401",
'question'="%CE%D2%D7%EE%B0%AE%B5%C4%C8%CB%B5%C4%C3%FB%D7%D6",
'answer'="tomtommail",
'checkuname'="on",
'uid'="prpdiyicitest",
'hid_pwd'="123456",
'password'="123456",
'hid_pwdcfm'="123456",
'confirm_password'="123456",
'safemail'="qqqqq@qq.com",
'authcode'=
#here is the test of the captha;
'argee_c'="yes"
};
postData = urllib.urlencode(postDict);
req = urllib2.Request(MainLoginUrl, postData);
req.add_header('Content-Type', "application/x-www-form-urlencoded"); if __name__=="__main__":
emulateLoginTom();
关于authcode里的数据我用api可以直接返回一个text，而这个text的前期是我上传一个本地图片，所以我需要在代码中打了一排#的地方把图片载下来……但是不会弄……求大神教