豆瓣top250（go版以及python版）

  最近学习go,就找了一个例子练习【go语言爬虫】go语言爬取豆瓣电影top250，思路大概就是获取网页，然后根据页面元素，用正则表达式匹配电影名称、评分、评论人数。原文有个地方需要修改下pattern4 := <img width="100" alt="(.*?)" src=，这样就能运行了

这个例子可以由修改下变成并发的形式，提高性能（参考golang 并发 chan）

var sem chan int = make(chan int,10);
   for i := 0; i < 10; i++ {
   	go func(i int) {
   		header := map[string]string{
   			"Host":                      "movie.douban.com",
   			"Connection":                "keep-alive",
   			"Cache-Control":             "max-age=0",
   			"Upgrade-Insecure-Requests": "1",
   			"User-Agent":                "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36",
   			"Accept":                    "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
   			"Referer":                   "https://movie.douban.com/top250",
   		}
   		fmt.Println("正在抓取第" + strconv.Itoa(i) + "页......")
   		url := "https://movie.douban.com/top250?start=" + strconv.Itoa(i*25) + "&filter="
   		spider := &Spider{url, header}
   		html := spider.get_html_header()

   		pattern2 := `<span>(.*?)评价</span>`
   		rp2 := regexp.MustCompile(pattern2)
   		find_txt2 := rp2.FindAllStringSubmatch(html, -1)

   		pattern3 := `property="v:average">(.*?)</span>`
   		rp3 := regexp.MustCompile(pattern3)
   		find_txt3 := rp3.FindAllStringSubmatch(html, -1)

   		pattern4 := `<img width="100" alt="(.*?)" src=`
   		rp4 := regexp.MustCompile(pattern4)
   		find_txt4 := rp4.FindAllStringSubmatch(html, -1)

   		for i := 0; i < len(find_txt2); i++ {
   			fmt.Printf("%s %s %s\n", find_txt4[i][1], find_txt3[i][1], find_txt2[i][1], )
   			f.WriteString(find_txt4[i][1] + "\t" + find_txt3[i][1] + "\t" + find_txt2[i][1] + "\t" + "\r\n")

   		}
   		sem <- 0
   	}(i)
   }
   for i := 0; i < 10; i++ { <-sem }
   close(sem)

  到这里go爬虫部分已经介绍完毕，百无聊赖之际又写了一个python版，python很简洁

# coding=utf-8  #
import re
import urllib2
import datetime
def getDouban(i):
    print "爬取第" + str(i)+"页"
    html = "https://movie.douban.com/top250?start=" + str(i) + "&filter="
    try:
        page = urllib2.urlopen(html, timeout=3)
        result = page.read()
        score = re.findall('property="v:average">(.*?)</span>',result)
        person = re.findall('<span>(.*?)评价</span>',result)
        name= re.findall('<img width="100" alt="(.*?)" src=', result)
        j=0
        while j<len(name):
            print name[j], score[j]+'分', person[j]
            j=j+1
    except:
        print i
starttime = datetime.datetime.now()
params=[]
for i in range(25):
    getDouban(i)
endtime = datetime.datetime.now()
print "爬虫历时"+str((endtime-starttime).seconds)+"s完成"