python网络爬虫

#!/usr/bin/python
import re
import urllib

def downURL(url,filename):
    #print url
    print filename
    try:
        fp = urllib.urlopen(url)
    except:
        print 'download exception'
        return 0
    op = open(filename,"wb")
    while 1:
        s = fp.read()
        if not s:
            break
        op.write(s)

    op.close()
    fp.close()
    return 1

def getURL(url):
    try:
        fp = urllib.urlopen(url)
    except:
        print 'get url exception'
        return 0

    pattern = re.compile("*.sina.com.cn.*.shtml")
    while 1:
        s = fp.read()
        if not s:
            break
        urls = pattern.findall(s)
    fp.close()
    return urls

def spider(startURL,times):
    urls = []
    urls.append(startURL)
    i = 0
    while 1:
        if i > times:
            break;
        if len(urls)>0:
            url = urls.pop(0)
            print url,len(urls), str(i)
            downURL(url,str(i)+'.htm')
            i = i + 1
            if len(urls)<times:
                urllist = getURL(url)
                for url in urllist:
                    if urls.count(url) == 0:
                        urls.append(url)
        else:
            break
    return 0

#downURL('','http.log')
spider('.cn',30)