[root@~]# python

 

Python 2.4.3 (#1, May  5 2011, 16:39:10)  

[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>;>>

[root@~]#

下载新版本的python

[root@~]# wget

 

解压缩 以及编译

[root@~]# tar jxvf Python-2.7.3.tar.bz2

[root@wangyuelou Python-2.7.2]# ./configure --prefix=/usr/local/python27

[root@wangyuelou Python-2.7.2]# make

[root@wangyuelou Python-2.7.2]# make install

[root@wangyuelou Python-2.7.2]# ls /usr/local/python27/ -al

total 28

drwxr-xr-x  6 root root 4096 Jul 14 00:21 .

drwxr-xr-x 20 root root 4096 Jul 14 00:17 ..

drwxr-xr-x  2 root root 4096 Jul 14 00:21 bin

drwxr-xr-x  3 root root 4096 Jul 14 00:21 include

drwxr-xr-x  4 root root 4096 Jul 14 00:21 lib

drwxr-xr-x  3 root root 4096 Jul 14 00:21 share

覆盖原来的python链接

[root@wangyuelou Python-2.7.2]# mv /usr/bin/python /usr/bin/python_old

[root@wangyuelou Python-2.7.2]# ln -s /usr/local/python27/bin/python /usr/bin/

[root@wangyuelou Python-2.7.2]# python

Python 2.7.2 (default, Jul 14 2011, 00:20:14)

[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>>

此处已经可以正常使用python2.7了

但是因为yum是使用的2.4的版本来用的，所以 还需要修改一下

[root@~]# yum

There was a problem importing one of the Python modules

required to run yum. The error leading to this problem was:

 

   No module named yum

 

Please install a package which provides this module, or

verify that the module is installed correctly.

 

It's possible that the above module doesn't match the

current version of Python, which is:

2.7.2 (default, Jul 14 2011, 00:20:14)

[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)]

 

If you cannot solve this problem yourself, please go to

the yum faq at:

 

 

[root@wangyuelou Python-2.7.2]# vim /usr/bin/yum

 

#!/usr/bin/python   #修改此处为2.4的位置

[root@~]# vim /usr/bin/yum

 

#!/usr/bin/python2.4

[root@~]# yum

Loaded plugins: fastestmirror

You need to give some command

usage: yum [options] COMMAND

 

List of Commands:

 

check-update   Check for available package updates

clean          Remove cached data

deplist        List a package's dependencies

downgrade      downgrade a package

erase          Remove a package or packages from your system

groupinfo      Display details about a package group

groupinstall   Install the packages in a group on your system

grouplist      List available package groups

groupremove    Remove the packages in a group from your system

help           Display a helpful usage message

info           Display details about a package or group of packages

install        Install a package or packages on your system

list           List a package or groups of packages

localinstall   Install a local RPM

yum 又可以使用了)

 

# Process the JSON string.

results = simplejson.load(response)

# now have some fun with the results...

 

实际应用中可能需要抓取google的很多网页，所以还需要使用多线程来分担抓取任务。使用google web search api的参考详细介绍，请看此处（这里介绍了Standard URL Arguments）。另外要特别注意，url中参数rsz必须是8（包括8）以下的值，若大于8，会报错的！

（3）代码实现

代码实现还存在问题，但是能够运行，鲁棒性差，还需要进行改进，希望各路大神指出错误（初学Python），不胜感激。

#-*-coding:utf-8-*-  

import urllib2,urllib

import simplejson

import os, time,threading

 

import common, html_filter

#input the keywords  

keywords = raw_input('Enter the keywords: ')                                  

 

#define rnum_perpage, pages  

rnum_perpage=8

pages=8                        

 

#定义线程函数  

def thread_scratch(url, rnum_perpage, page):

url_set = []  

try:

  request = urllib2.Request(url, None, {'Referer': 'http://www.sina.com'})

  response = urllib2.urlopen(request)

  # Process the JSON string.  

  results = simplejson.load(response)

  info = results['responseData']['results']

except Exception,e:

  print 'error occured'

  print e

else:

  for minfo in info:

     url_set.append(minfo['url'])

     print minfo['url']

 #处理链接  

i = 0

for u in url_set:

  try:

    request_url = urllib2.Request(u, None, {'Referer': 'http://www.sina.com'})

    request_url.add_header(

    'User-agent',

    'CSC'

    )

    response_data = urllib2.urlopen(request_url).read()

    #过滤文件  

    #content_data = html_filter.filter_tags(response_data)  

    #写入文件  

    filenum = i+page

    filename = dir_name+'/related_html_'+str(filenum)

    print '  write start: related_html_'+str(filenum)

    f = open(filename, 'w+', -1)

    f.write(response_data)

    #print content_data  

    f.close()

    print '  write down: related_html_'+str(filenum)

  except Exception, e:

    print 'error occured 2'

    print e

  i = i+1

return  

 

#创建文件夹  

dir_name = 'related_html_'+urllib.quote(keywords)

if os.path.exists(dir_name):

  print 'exists  file'

  common.delete_dir_or_file(dir_name)

os.makedirs(dir_name)

 

#抓取网页  

print 'start to scratch web pages:'

for x in range(pages):

 print "page:%s"%(x+1)

 page = x * rnum_perpage

 url = ('https://ajax.googleapis.com/ajax/services/search/web'

                 '?v=1.0&q=%s&rsz=%s&start=%s') % (urllib.quote(keywords), rnum_perpage,page)

 print url

 t = threading.Thread(target=thread_scratch, args=(url,rnum_perpage, page))

 t.start()

#主线程等待子线程抓取完  

main_thread = threading.currentThread()

for t in threading.enumerate():

 if t is main_thread:

   continue

 t.join()