大多数APP里面返回的是json格式数据，或者一堆加密过的数据 。这里以超级课程表APP为例，抓取超级课程表里用户发的话题。

1、抓取APP数据包

方法详细可以参考这篇博文：Fiddler如何抓取手机APP数据包

得到超级课程表登录的地址：http://120.55.151.61/V2/StudentSkip/loginCheckV4.action

表单：

表单中包括了用户名和密码，当然都是加密过了的，还有一个设备信息，直接post过去就是。

另外必须加header,一开始我没有加header得到的是登录错误，所以要带上header信息。

2、登录

登录代码：

import urllib2
from cookielib import CookieJar
loginUrl = \'http://120.55.151.61/V2/StudentSkip/loginCheckV4.action\'
headers = {
\'Content-Type\': \'application/x-www-form-urlencoded; charset=UTF-8\',
\'User-Agent\': \'Dalvik/1.6.0 (Linux; U; Android 4.1.1; M040 Build/JRO03H)\',
\'Host\': \'120.55.151.61\',
\'Connection\': \'Keep-Alive\',
\'Accept-Encoding\': \'gzip\',
\'Content-Length\': \'207\',
}
loginData = \'phoneBrand=Meizu&platform=1&deviceCode=868033014919494&account=FCF030E1F2F6341C1C93BE5BBC422A3D&phoneVersion=16&password=A55B48BB75C79200379D82A18C5F47D6&channel=MXMarket&phoneModel=M040&versionNumber=7.2.1&\'
cookieJar = CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookieJar))
req = urllib2.Request(loginUrl, loginData, headers)
loginResult = opener.open(req).read()
print loginResult

登录成功 会返回一串账号信息的json数据

和抓包时返回数据一样，证明登录成功

3、抓取数据

用同样方法得到话题的url和post参数

做法就和模拟登录网站一样。详见：Python爬虫模拟登录带验证码网站

下见最终代码，有主页获取和下拉加载更新。可以无限加载话题内容。

#!/usr/local/bin/python2.7
# -*- coding: utf8 -*-
\"\"\"
超级课程表话题抓取
\"\"\"
import urllib2
from cookielib import CookieJar
import json
\'\'\' 读Json数据 \'\'\'
def fetch_data(json_data):
data = json_data[\'data\']
timestampLong = data[\'timestampLong\']
messageBO = data[\'messageBOs\']
topicList = []
for each in messageBO:
topicDict = {}
if each.get(\'content\', False):
topicDict[\'content\'] = each[\'content\']
topicDict[\'schoolName\'] = each[\'schoolName\']
topicDict[\'messageId\'] = each[\'messageId\']
topicDict[\'gender\'] = each[\'studentBO\'][\'gender\']
topicDict[\'time\'] = each[\'issueTime\']
print each[\'schoolName\'],each[\'content\']
topicList.append(topicDict)
return timestampLong, topicList
\'\'\' 加载更多 \'\'\'
def load(timestamp, headers, url):
headers[\'Content-Length\'] = \'159\'
loadData = \'timestamp=%s&phoneBrand=Meizu&platform=1&genderType=-1&topicId=19&phoneVersion=16&selectType=3&channel=MXMarket&phoneModel=M040&versionNumber=7.2.1&\' % timestamp
req = urllib2.Request(url, loadData, headers)
loadResult = opener.open(req).read()
loginStatus = json.loads(loadResult).get(\'status\', False)
if loginStatus == 1:
print \'load successful!\'
timestamp, topicList = fetch_data(json.loads(loadResult))
load(timestamp, headers, url)
else:
print \'load fail\'
print loadResult
return False
loginUrl = \'http://120.55.151.61/V2/StudentSkip/loginCheckV4.action\'
topicUrl = \'http://120.55.151.61/V2/Treehole/Message/getMessageByTopicIdV3.action\'
headers = {
\'Content-Type\': \'application/x-www-form-urlencoded; charset=UTF-8\',
\'User-Agent\': \'Dalvik/1.6.0 (Linux; U; Android 4.1.1; M040 Build/JRO03H)\',
\'Host\': \'120.55.151.61\',
\'Connection\': \'Keep-Alive\',
\'Accept-Encoding\': \'gzip\',
\'Content-Length\': \'207\',
}
\'\'\' ---登录部分--- \'\'\'
loginData = \'phoneBrand=Meizu&platform=1&deviceCode=868033014919494&account=FCF030E1F2F6341C1C93BE5BBC422A3D&phoneVersion=16&password=A55B48BB75C79200379D82A18C5F47D6&channel=MXMarket&phoneModel=M040&versionNumber=7.2.1&\'
cookieJar = CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookieJar))
req = urllib2.Request(loginUrl, loginData, headers)
loginResult = opener.open(req).read()
loginStatus = json.loads(loginResult).get(\'data\', False)
if loginResult:
print \'login successful!\'
else:
print \'login fail\'
print loginResult
\'\'\' ---获取话题--- \'\'\'
topicData = \'timestamp=0&phoneBrand=Meizu&platform=1&genderType=-1&topicId=19&phoneVersion=16&selectType=3&channel=MXMarket&phoneModel=M040&versionNumber=7.2.1&\'
headers[\'Content-Length\'] = \'147\'
topicRequest = urllib2.Request(topicUrl, topicData, headers)
topicHtml = opener.open(topicRequest).read()
topicJson = json.loads(topicHtml)
topicStatus = topicJson.get(\'status\', False)
print topicJson
if topicStatus == 1:
print \'fetch topic success!\'
timestamp, topicList = fetch_data(topicJson)
load(timestamp, headers, topicUrl)

结果：