# -*- coding: GB2312 -*-

from urllib import urlencode
import cookielib, urllib2

# cookie
cj = cookielib.LWPCookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
urllib2.install_opener(opener)

# Login
user_data = {'pwuser': '你的用户名',
       'pwpwd': '你的密码',
       'step':'2'
      }
url_data = urlencode(user_data)
login_r = opener.open("http://bbs.qzzn.com/login.php", url_data)

<form action="login.php?" method="post" name="login" onSubmit="this.submit.disabled = true;"> 
<input type="hidden" value="" name="forward" /> 
<input type="hidden" value="http://bbs.qzzn.com/index.php" name="jumpurl" /> 
<input type="hidden" value="2" name="step" /> 
... 
<td width="20%" onclick="document.login.pwuser.focus();"><input type="radio" name="lgt" value="0" checked />用户名 <input type="radio" name="lgt" value="1" />UID</td> 
<td><input class="input" type="text" maxLength="20" name="pwuser" size="40" tabindex="1" /> <a href="reg1ster.php" rel="external nofollow" >马上注册</a></td> 
<td>密　码</td> 
<td><input class="input" type="password" maxLength="20" name="pwpwd" size="40" tabindex="2" /> <a href="sendpwd.php" rel="external nofollow" target="_blank">找回密码</a></td> 
... 
</form>