出差时写的一个抓取baidu图片的东东

使用了多线程但没有处理同步。
正则表达式是用kodos弄出来的，这个工具使用起来比较顺手。

#!/usr/bin/env python
#coding=cp936

import re
import urllib
import thread
import time

#url_part1 = '''http://images.google.cn/images?q='''
#url_part2 = '''&svnum=10&hl=zh-CN&lr=&newwindow=1&start='''
#url_part3 = '''&sa=N'''
url_part1 = '''http://image.baidu.com/i?z=0&cl=2&ct=201326592&sn=&lm=-1&cm=1&sc=0&bu=&rn=16&tn=baiduimage&word='''
url_part2 = '''&pn='''


def nextpage(keywords,start):
    return url_part1 + urllib.quote(keywords) + url_part2 + str(start)

#compile_obj = re.compile(r'dyn.Img\("http://(.)+","","","')
compile_obj = re.compile(r'<a href="http://image.baidu.com/ir\?t=1&u=http://(.)+&f=http://')

def parseurl(content):
    ret = []
    match_objs = compile_obj.finditer(content)
    for match in match_objs:
        url = match.group().split('&')[1][2:]
        ret.append(url)
    return ret

#exitdic = {}

def downimg(url,exitdic):
    filename = url.split('/')[-1]
    #print url,'---->',filename
    urllib.urlretrieve(url,filename)
    exitdic[url].acquire()

def download(url):
    exitdic = {}
    print '开始下载页面: ' + url
    conn = urllib.urlopen(url)
    content = conn.read()
    conn.close()
    urls = parseurl(content)
    for url in urls:
        print url
        exitdic[url] = thread.allocate_lock()
        thread.start_new(downimg,(url,exitdic))
    
    for key in exitdic.keys():
        while not exitdic[key].locked():
            #time.sleep(200)
            pass
    print '完成一页'

#抓取关键字为vista的图片，抓取范围为查询结果的第4到8页
if __name__ == '__main__':
    for i in range(4,8):
        url = nextpage('vista',i*16)
        download(url)
    
    print 'OK'