如何写个爬虫程序扒下知乎某个回答所有点赞用户名单？

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import requests
from bs4 import BeautifulSoup
import time
import json
import os
import sys

url = 'http://www.zhihu.com'
loginURL = 'http://www.zhihu.com/login/email'

headers = {
    "User-Agent": 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:41.0) Gecko/20100101 Firefox/41.0',
    "Referer": "http://www.zhihu.com/",
    'Host': 'www.zhihu.com',
}

data = {
    'email': '
xxxxx@gmail.com',
    'password': '
xxxxxxx',
    'rememberme': "true",
}

s = requests.session()
# 如果成功登陆过,用保存的cookies登录
if os.path.exists('cookiefile'):
    with open('cookiefile') as f:
        cookie = json.load(f)
    s.cookies.update(cookie)
    req1 = s.get(url, headers=headers)
    with open('zhihu.html', 'w') as f:
        f.write(req1.content)
# 第一次需要手动输入验证码登录
else:
    req = s.get(url, headers=headers)
    print req

    soup = BeautifulSoup(req.text, "html.parser")
    xsrf = soup.find('input', {'name': '_xsrf', 'type': 'hidden'}).get('value')

    data['_xsrf'] = xsrf

    timestamp = int(time.time() * 1000)
    captchaURL = 'http://www.zhihu.com/captcha.gif?=' + str(timestamp)
    print captchaURL

    with open('zhihucaptcha.gif', 'wb') as f:
        captchaREQ = s.get(captchaURL)
        f.write(captchaREQ.content)
    loginCaptcha = raw_input('input captcha:\n').strip()
    data['captcha'] = loginCaptcha
    # print data
    loginREQ = s.post(loginURL,  headers=headers, data=data)
    # print loginREQ.url
    # print s.cookies.get_dict()
    if not loginREQ.json()['r']:
        # print loginREQ.json()
        with open('cookiefile', 'wb') as f:
            json.dump(s.cookies.get_dict(), f)
    else:
        print 'login failed, try again!'
        sys.exit(1)

# 以http://www.zhihu.com/question/27621722/answer/48820436这个大神的399各赞为例子.
zanBaseURL = 'http://www.zhihu.com/answer/22229844/voters_profile?&offset={0}'
page = 0
count = 0
while 1:
    zanURL = zanBaseURL.format(str(page))
    page += 10
    zanREQ = s.get(zanURL, headers=headers)
    zanData = zanREQ.json()['payload']
    if not zanData:
        break
    for item in zanData:
        # print item
        zanSoup = BeautifulSoup(item, "html.parser")
        zanInfo = zanSoup.find('a', {'target': "_blank", 'class': 'zg-link'})
        if zanInfo:
            print 'nickname:', zanInfo.get('title'),  '    ',
            print 'person_url:', zanInfo.get('href')
        else:
            anonymous = zanSoup.find(
                'img', {'title': True, 'class': "zm-item-img-avatar"})
            print 'nickname:', anonymous.get('title')

        count += 1
    print count

from zhihu import ZhihuClient

client = ZhihuClient('cookies.json')

url = 'http://www.zhihu.com/question/36338520/answer/67029821'
answer = client.answer(url)

print('问题：{0}'.format(answer.question.title))
print('答主：{0}'.format(answer.author.name))
print('此答案共有{0}人点赞：\n'.format(answer.upvote_num))

for upvoter in answer.upvoters:
    print(upvoter.name, upvoter.url)

<div data-copyable="1" data-isowner="0" data-helpful="1" data-deleted="0" data-created="1444404675" data-collapsed="0" data-atoken="67029821" data-author="洛克" data-qtoken="36338520" data-aid="22229844" itemtype="http://schema.org/Answer" itemscope="" itemprop="topAnswer" class="zm-item-answer" tabindex="-1">