Python with verification code to achieve the automatic landing of the site code

Early heard that using python to do web crawler is very convenient, just these days the unit also has such a demand, need to log on to the XX website to download part of the document, so their own personal experiment, the effect is not bad.

In this example, a website logged in needs to provide the user name, password and verification code. In this case, python urllib2 is used to log into the website directly and process the website's cookies.

How cookies work:
The Cookie is generated by the server and sent to the browser, which saves the Cookie in a text file in a directory. The next time the same website is requested, the Cookie is sent to the server so the server knows if the user is legitimate and needs to log back in.

Python provides the basic cookielib library, where cookies are automatically saved the first time you visit a page, and cookies that are normally logged in are always present when you visit other pages.

Principle:

(1) activate the cookie function
(2) anti-" anti-hotlinking ", disguised as browser access
(3) visit the verification code link and download the verification code picture to the local
(4) there are many verification code identification schemes on the network, and python also has its own image processing library. This example calls the OCR identification interface of locomotive collector.
(5) form processing, you can use fiddler and other grab tools to get the parameters to be submitted
(6) generate the data to be submitted, generate the HTTP request and send it
(7) judge whether the login is successful according to the returned js page
(8) download other pages after successful login

In this example, multiple accounts are used to poll login and each account downloads 3 pages.

The download url is not disclosed because of some problems.

Here is part of the code:

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

import os
import urllib2
import urllib
import cookielib
import xml.etree.ElementTree as ET


#-----------------------------------------------------------------------------
# Login in www.***.com.cn
def ChinaBiddingLogin(url, username, password):
    # Enable cookie support for urllib2
    cookiejar=cookielib.CookieJar()
    urlopener=urllib2.build_opener(urllib2.HTTPCookieProcessor(cookiejar))
    urllib2.install_opener(urlopener)
    
    urlopener.addheaders.append(('Referer', 'http://www.chinabidding.com.cn/zbw/login/login.jsp'))
    urlopener.addheaders.append(('Accept-Language', 'zh-CN'))
    urlopener.addheaders.append(('Host', 'www.chinabidding.com.cn'))
    urlopener.addheaders.append(('User-Agent', 'Mozilla/5.0 (compatible; MISE 9.0; Windows NT 6.1); Trident/5.0'))
    urlopener.addheaders.append(('Connection', 'Keep-Alive'))


    print 'XXX Login......'


    imgurl=r'http://www.*****.com.cn/zbw/login/image.jsp'
    DownloadFile(imgurl, urlopener)
    authcode=raw_input('Please enter the authcode:')
    #authcode=VerifyingCodeRecognization(r"http://192.168.0.106/images/code.jpg")


    # Send login/password to the site and get the session cookie
    values={'login_id':username, 'opl':'op_login', 'login_passwd':password, 'login_check':authcode}
    urlcontent=urlopener.open(urllib2.Request(url, urllib.urlencode(values)))
    page=urlcontent.read(500000)


    # Make sure we are logged in, check the returned page content
    if page.find('login.jsp')!=-1:
        print 'Login failed with username=%s, password=%s and authcode=%s' 
                % (username, password, authcode)
        return False
    else:
        print 'Login succeeded!'
        return True


#-----------------------------------------------------------------------------
# Download from fileUrl then save to fileToSave
# Note: the fileUrl must be a valid file
def DownloadFile(fileUrl, urlopener):
    isDownOk=False


    try:
        if fileUrl:
            outfile=open(r'/var/www/images/code.jpg', 'w')
            outfile.write(urlopener.open(urllib2.Request(fileUrl)).read())
            outfile.close()


            isDownOK=True
        else:
            print 'ERROR: fileUrl is NULL!'
    except:
        isDownOK=False


    return isDownOK


#------------------------------------------------------------------------------
# Verifying code recoginization
def VerifyingCodeRecognization(imgurl):
    url=r'http://192.168.0.119:800/api?'
    user='admin'
    pwd='admin'
    model='ocr'
    ocrfile='cbi'


    values={'user':user, 'pwd':pwd, 'model':model, 'ocrfile':ocrfile, 'imgurl':imgurl}
    data=urllib.urlencode(values)


    try:
        url+=data
        urlcontent=urllib2.urlopen(url)
    except IOError:
        print '***ERROR: invalid URL (%s)' % url


    page=urlcontent.read(500000)


    # Parse the xml data and get the verifying code
    root=ET.fromstring(page)
    node_find=root.find('AddField')
    authcode=node_find.attrib['data']


    return authcode


#------------------------------------------------------------------------------
# Read users from configure file
def ReadUsersFromFile(filename):
    users={}
    for eachLine in open(filename, 'r'):
        info=[w for w in eachLine.strip().split()]
        if len(info)==2:
            users[info[0]]=info[1]


    return users


#------------------------------------------------------------------------------
def main():
    login_page=r'http://www.***.com.cnlogin/login.jsp'
    download_page=r'http://www.***.com.cn***/***?record_id='


    start_id=8593330
    end_id=8595000


    now_id=start_id
    Users=ReadUsersFromFile('users.conf')
    while True:
        for key in Users:
            if ChinaBiddingLogin(login_page, key, Users[key]):
                for i in range(3):
                    pageUrl=download_page+'%d' % now_id
                    urlcontent=urllib2.urlopen(pageUrl)


                    filepath='./download/%s.html' % now_id
                    f=open(filepath, 'w')
                    f.write(urlcontent.read(500000))
                    f.close()


                    now_id+=1
            else:
                continue
#------------------------------------------------------------------------------


if __name__=='__main__':
    main()