之前已经介绍过了网络相关的一些基础知识了:
【整理】关于抓取网页,分析网页内容,模拟登陆网站的逻辑/流程和注意事项
以及,简单的网页内容抓取,用Python是如何实现的:
现在接着来介绍,如何通过Python来实现基本的模拟网站登陆的流程。
不过,此处需要介绍一下此文前提:
假定你已经看完了:
【整理】关于抓取网页,分析网页内容,模拟登陆网站的逻辑/流程和注意事项
了解了基本的网络相关基本概念;
看完了:
【总结】浏览器中的开发人员工具(IE9的F12和Chrome的Ctrl+Shift+I)-网页分析的利器
知道了如何使用IE9的F12等工具去分析网页执行的过程。
此处已模拟登陆百度首页:
为例,说明如何通过Python模拟登陆网站。
1.模拟登陆网站之前,需要搞清楚,登陆该网站的内部执行逻辑
此想要通过程序,python代码,实现模拟登陆百度首页之前。
你自己本身先要搞懂,本身登陆该网站,内部的逻辑是什么样的。
而关于如何利用工具,分析出来,百度首页登录的内部逻辑过程,参见:
【教程】手把手教你如何利用工具(IE9的F12)去分析模拟登陆网站(百度首页)的内部逻辑过程
2.然后才是用对应的语言,此处是Python去实现,模拟登陆的逻辑
看懂了上述用F12分析出来的百度首页的登陆的内部逻辑过程,接下来,用Python代码去实现,相对来说,就不是很难了。
注:
(1)关于在Python中如何利用cookie,不熟悉的,先去看:
【已解决】Python中如何获得访问网页所返回的cookie
【已解决】Python中实现带Cookie的Http的Post请求
(2)对于正则表达式不熟悉的,去参考:
(3)对python的正则表达式不熟悉的,可参考:
此处,再把分析出来的流程,贴出来,以便方便和代码对照:
顺序 | 访问地址 | 访问类型 | 发送的数据 | 需要获得/提取的返回的值 |
1 | http://www.baidu.com/ | GET | 无 | 返回的cookie中的BAIDUID |
2 | https://passport.baidu.com/v2/api/?getapi&class=login&tpl=mn&tangram=true | GET | 包含BAIDUID这个cookie | 从返回的html中提取出token的值 |
3 | https://passport.baidu.com/v2/api/?login | POST | 一堆的post data,其中token的值是之前提取出来的 | 需要验证返回的cookie中,是否包含BDUSS,PTOKEN,STOKEN,SAVEUSERID |
然后,最终就可以写出相关的,用于演示模拟登录百度首页的Python代码了。
【版本1:Python实现模拟登陆百度首页的完整代码 之 精简版】
这个是相对精简的一个版本:
#!/usr/bin/python # -*- coding: utf-8 -*- """ Function: Used to demostrate how to use Python code to emulate login baidu main page: http://www.baidu.com/ Note: Before try to understand following code, firstly, please read the related articles: (1)【整理】关于抓取网页,分析网页内容,模拟登陆网站的逻辑/流程和注意事项 https://www.crifan.com/summary_about_flow_process_of_fetch_webpage_simulate_login_website_and_some_notice/ (2) 【教程】手把手教你如何利用工具(IE9的F12)去分析模拟登陆网站(百度首页)的内部逻辑过程 https://www.crifan.com/use_ie9_f12_to_analysis_the_internal_logical_process_of_login_baidu_main_page_website/ (3) 【教程】模拟登陆网站 之 Python版 https://www.crifan.com/emulate_login_website_using_python Version: 2012-11-06 Author: Crifan """ import re; import cookielib; import urllib; import urllib2; import optparse; #------------------------------------------------------------------------------ # check all cookies in cookiesDict is exist in cookieJar or not def checkAllCookiesExist(cookieNameList, cookieJar) : cookiesDict = {}; for eachCookieName in cookieNameList : cookiesDict[eachCookieName] = False; allCookieFound = True; for cookie in cookieJar : if(cookie.name in cookiesDict) : cookiesDict[cookie.name] = True; for eachCookie in cookiesDict.keys() : if(not cookiesDict[eachCookie]) : allCookieFound = False; break; return allCookieFound; #------------------------------------------------------------------------------ # just for print delimiter def printDelimiter(): print '-'*80; #------------------------------------------------------------------------------ # main function to emulate login baidu def emulateLoginBaidu(): print "Function: Used to demostrate how to use Python code to emulate login baidu main page: http://www.baidu.com/"; print "Usage: emulate_login_baidu_python.py -u yourBaiduUsername -p yourBaiduPassword"; printDelimiter(); # parse input parameters parser = optparse.OptionParser(); parser.add_option("-u","--username",action="store",type="string",default='',dest="username",help="Your Baidu Username"); parser.add_option("-p","--password",action="store",type="string",default='',dest="password",help="Your Baidu password"); (options, args) = parser.parse_args(); # export all options variables, then later variables can be used for i in dir(options): exec(i + " = options." + i); printDelimiter(); print "[preparation] using cookieJar & HTTPCookieProcessor to automatically handle cookies"; cj = cookielib.CookieJar(); opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)); urllib2.install_opener(opener); printDelimiter(); print "[step1] to get cookie BAIDUID"; baiduMainUrl = "http://www.baidu.com/"; resp = urllib2.urlopen(baiduMainUrl); #respInfo = resp.info(); #print "respInfo=",respInfo; for index, cookie in enumerate(cj): print '[',index, ']',cookie; printDelimiter(); print "[step2] to get token value"; getapiUrl = "https://passport.baidu.com/v2/api/?getapi&class=login&tpl=mn&tangram=true"; getapiResp = urllib2.urlopen(getapiUrl); #print "getapiResp=",getapiResp; getapiRespHtml = getapiResp.read(); #print "getapiRespHtml=",getapiRespHtml; #bdPass.api.params.login_token='5ab690978812b0e7fbbe1bfc267b90b3'; foundTokenVal = re.search("bdPass\.api\.params\.login_token='(?P<tokenVal>\w+)';", getapiRespHtml); if(foundTokenVal): tokenVal = foundTokenVal.group("tokenVal"); print "tokenVal=",tokenVal; printDelimiter(); print "[step3] emulate login baidu"; staticpage = "http://www.baidu.com/cache/user/html/jump.html"; baiduMainLoginUrl = "https://passport.baidu.com/v2/api/?login"; postDict = { #'ppui_logintime': "", 'charset' : "utf-8", #'codestring' : "", 'token' : tokenVal, #de3dbf1e8596642fa2ddf2921cd6257f 'isPhone' : "false", 'index' : "0", #'u' : "", #'safeflg' : "0", 'staticpage' : staticpage, #http%3A%2F%2Fwww.baidu.com%2Fcache%2Fuser%2Fhtml%2Fjump.html 'loginType' : "1", 'tpl' : "mn", 'callback' : "parent.bdPass.api.login._postCallback", 'username' : username, 'password' : password, #'verifycode' : "", 'mem_pass' : "on", }; postData = urllib.urlencode(postDict); # here will automatically encode values of parameters # such as: # encode http://www.baidu.com/cache/user/html/jump.html into http%3A%2F%2Fwww.baidu.com%2Fcache%2Fuser%2Fhtml%2Fjump.html #print "postData=",postData; req = urllib2.Request(baiduMainLoginUrl, postData); # in most case, for do POST request, the content-type, is application/x-www-form-urlencoded req.add_header('Content-Type', "application/x-www-form-urlencoded"); resp = urllib2.urlopen(req); #for index, cookie in enumerate(cj): # print '[',index, ']',cookie; cookiesToCheck = ['BDUSS', 'PTOKEN', 'STOKEN', 'SAVEUSERID']; loginBaiduOK = checkAllCookiesExist(cookiesToCheck, cj); if(loginBaiduOK): print "+++ Emulate login baidu is OK, ^_^"; else: print "--- Failed to emulate login baidu !" else: print "Fail to extract token value from html=",getapiRespHtml; if __name__=="__main__": emulateLoginBaidu();
【版本2:Python实现模拟登陆百度首页的完整代码 之 crifanLib.py版】
这个是另外一个版本,其中利用到我自己的python库:crifanLib.py :
#!/usr/bin/python # -*- coding: utf-8 -*- """ Function: Used to demostrate how to use Python code to emulate login baidu main page: http://www.baidu.com/ Use the functions from crifanLib.py Note: Before try to understand following code, firstly, please read the related articles: (1)【整理】关于抓取网页,分析网页内容,模拟登陆网站的逻辑/流程和注意事项 https://www.crifan.com/summary_about_flow_process_of_fetch_webpage_simulate_login_website_and_some_notice/ (2) 【教程】手把手教你如何利用工具(IE9的F12)去分析模拟登陆网站(百度首页)的内部逻辑过程 https://www.crifan.com/use_ie9_f12_to_analysis_the_internal_logical_process_of_login_baidu_main_page_website/ (3) 【教程】模拟登陆网站 之 Python版 https://www.crifan.com/emulate_login_website_using_python Version: 2012-11-07 Author: Crifan Contact: admin (at) crifan.com """ import re; import cookielib; import urllib; import urllib2; import optparse; #=============================================================================== # following are some functions, extracted from my python library: crifanLib.py # for the whole crifanLib.py: # online browser: http://code.google.com/p/crifanlib/source/browse/trunk/python/crifanLib.py # download : http://code.google.com/p/crifanlib/downloads/list #=============================================================================== import zlib; gConst = { 'constUserAgent' : 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3; .NET4.0C; .NET4.0E)', #'constUserAgent' : "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101 Firefox/15.0.1", } ################################################################################ # Network: urllib/urllib2/http ################################################################################ #------------------------------------------------------------------------------ # get response from url # note: if you have already used cookiejar, then here will automatically use it # while using rllib2.Request def getUrlResponse(url, postDict={}, headerDict={}, timeout=0, useGzip=False) : # makesure url is string, not unicode, otherwise urllib2.urlopen will error url = str(url); if (postDict) : postData = urllib.urlencode(postDict); req = urllib2.Request(url, postData); req.add_header('Content-Type', "application/x-www-form-urlencoded"); else : req = urllib2.Request(url); if(headerDict) : #print "added header:",headerDict; for key in headerDict.keys() : req.add_header(key, headerDict[key]); defHeaderDict = { 'User-Agent' : gConst['constUserAgent'], 'Cache-Control' : 'no-cache', 'Accept' : '*/*', 'Connection' : 'Keep-Alive', }; # add default headers firstly for eachDefHd in defHeaderDict.keys() : #print "add default header: %s=%s"%(eachDefHd,defHeaderDict[eachDefHd]); req.add_header(eachDefHd, defHeaderDict[eachDefHd]); if(useGzip) : #print "use gzip for",url; req.add_header('Accept-Encoding', 'gzip, deflate'); # add customized header later -> allow overwrite default header if(headerDict) : #print "added header:",headerDict; for key in headerDict.keys() : req.add_header(key, headerDict[key]); if(timeout > 0) : # set timeout value if necessary resp = urllib2.urlopen(req, timeout=timeout); else : resp = urllib2.urlopen(req); return resp; #------------------------------------------------------------------------------ # get response html==body from url #def getUrlRespHtml(url, postDict={}, headerDict={}, timeout=0, useGzip=False) : def getUrlRespHtml(url, postDict={}, headerDict={}, timeout=0, useGzip=True) : resp = getUrlResponse(url, postDict, headerDict, timeout, useGzip); respHtml = resp.read(); if(useGzip) : #print "---before unzip, len(respHtml)=",len(respHtml); respInfo = resp.info(); # Server: nginx/1.0.8 # Date: Sun, 08 Apr 2012 12:30:35 GMT # Content-Type: text/html # Transfer-Encoding: chunked # Connection: close # Vary: Accept-Encoding # ... # Content-Encoding: gzip # sometime, the request use gzip,deflate, but actually returned is un-gzip html # -> response info not include above "Content-Encoding: gzip" # eg: http://blog.sina.com.cn/s/comment_730793bf010144j7_3.html # -> so here only decode when it is indeed is gziped data if( ("Content-Encoding" in respInfo) and (respInfo['Content-Encoding'] == "gzip")) : respHtml = zlib.decompress(respHtml, 16+zlib.MAX_WBITS); #print "+++ after unzip, len(respHtml)=",len(respHtml); return respHtml; ################################################################################ # Cookies ################################################################################ #------------------------------------------------------------------------------ # check all cookies in cookiesDict is exist in cookieJar or not def checkAllCookiesExist(cookieNameList, cookieJar) : cookiesDict = {}; for eachCookieName in cookieNameList : cookiesDict[eachCookieName] = False; allCookieFound = True; for cookie in cookieJar : if(cookie.name in cookiesDict) : cookiesDict[cookie.name] = True; for eachCookie in cookiesDict.keys() : if(not cookiesDict[eachCookie]) : allCookieFound = False; break; return allCookieFound; #=============================================================================== #------------------------------------------------------------------------------ # just for print delimiter def printDelimiter(): print '-'*80; #------------------------------------------------------------------------------ # main function to emulate login baidu def emulateLoginBaidu(): print "Function: Used to demostrate how to use Python code to emulate login baidu main page: http://www.baidu.com/"; print "Usage: emulate_login_baidu_python.py -u yourBaiduUsername -p yourBaiduPassword"; printDelimiter(); # parse input parameters parser = optparse.OptionParser(); parser.add_option("-u","--username",action="store",type="string",default='',dest="username",help="Your Baidu Username"); parser.add_option("-p","--password",action="store",type="string",default='',dest="password",help="Your Baidu password"); (options, args) = parser.parse_args(); # export all options variables, then later variables can be used for i in dir(options): exec(i + " = options." + i); printDelimiter(); print "[preparation] using cookieJar & HTTPCookieProcessor to automatically handle cookies"; cj = cookielib.CookieJar(); opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)); urllib2.install_opener(opener); printDelimiter(); print "[step1] to get cookie BAIDUID"; baiduMainUrl = "http://www.baidu.com/"; resp = getUrlResponse(baiduMainUrl); # here you should see: BAIDUID for index, cookie in enumerate(cj): print '[',index, ']',cookie; printDelimiter(); print "[step2] to get token value"; getapiUrl = "https://passport.baidu.com/v2/api/?getapi&class=login&tpl=mn&tangram=true"; getapiRespHtml = getUrlRespHtml(getapiUrl); #bdPass.api.params.login_token='5ab690978812b0e7fbbe1bfc267b90b3'; foundTokenVal = re.search("bdPass\.api\.params\.login_token='(?P<tokenVal>\w+)';", getapiRespHtml); if(foundTokenVal): tokenVal = foundTokenVal.group("tokenVal"); print "tokenVal=",tokenVal; printDelimiter(); print "[step3] emulate login baidu"; staticpage = "http://www.baidu.com/cache/user/html/jump.html"; baiduMainLoginUrl = "https://passport.baidu.com/v2/api/?login"; postDict = { #'ppui_logintime': "", 'charset' : "utf-8", #'codestring' : "", 'token' : tokenVal, #de3dbf1e8596642fa2ddf2921cd6257f 'isPhone' : "false", 'index' : "0", #'u' : "", #'safeflg' : "0", 'staticpage' : staticpage, #http%3A%2F%2Fwww.baidu.com%2Fcache%2Fuser%2Fhtml%2Fjump.html 'loginType' : "1", 'tpl' : "mn", 'callback' : "parent.bdPass.api.login._postCallback", 'username' : username, 'password' : password, #'verifycode' : "", 'mem_pass' : "on", }; loginRespHtml = getUrlRespHtml(baiduMainLoginUrl, postDict); cookiesToCheck = ['BDUSS', 'PTOKEN', 'STOKEN', 'SAVEUSERID']; loginBaiduOK = checkAllCookiesExist(cookiesToCheck, cj); if(loginBaiduOK): print "+++ Emulate login baidu is OK, ^_^"; else: print "--- Failed to emulate login baidu !" else: print "Fail to extract token value from html=",getapiRespHtml; if __name__=="__main__": emulateLoginBaidu();
此版本的目的在于,方便后来人使用网络相关的函数,不用关心内部细节。
并且,相关的函数,也可以供以后再次利用。
注:关于crifanLib.py:
在线浏览:crifanLib.py
上述两种版本的代码,对应的输出,都是:
D:\tmp\tmp_dev_root\python\emulate_login_baidu_python>emulate_login_baidu_python.py -u crifan -p xxxxxx Function: Used to demostrate how to use Python code to emulate login baidu main page: http://www.baidu.com/ Usage: emulate_login_baidu_python.py -u yourBaiduUsername -p yourBaiduPassword -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- [preparation] using cookieJar & HTTPCookieProcessor to automatically handle cookies -------------------------------------------------------------------------------- [step1] to get cookie BAIDUID [ 0 ] <Cookie BAIDUID=8D85C6528FDF7B5F49C746A18524495B:FG=1 for .baidu.com/> -------------------------------------------------------------------------------- [step2] to get token value tokenVal= 4d3f004bbe3e6f0cfa435abd38dd9fec -------------------------------------------------------------------------------- [step3] emulate login baidu +++ Emulate login baidu is OK, ^_^
【总结】
总的来说,其实分析网站登陆的过程,所涉及的内部逻辑,其实比用代码写出来要难多了。
而分析网站登陆过程的大概逻辑,要比用工具去具体的分析,要重要的多。
而这一堆的过程,之前自己折腾时,也正是苦于无完整的教程,所以,才有现在的一堆的帖子,来从头到尾的解释,从概念,到逻辑,到分析,到实现的整个过程。
全部都看完,应该对这部分内容,就大概有个了解的。
剩下的东西,就是实际的操练了,就是自己折腾的过程了。
希望上述所有的概念,逻辑,方法,代码,对你有用。