Python3 定向爬虫之“抓取糗事百科图片”

#--*--coding:utf-8--*--
#抓取糗事百科图片，并保存到文件夹中

import re
import urllib.request
from urllib.error import URLError,HTTPError
import sys

url = "http://www.qiushibaike.com/imgrank/page/1"
# 给文件加入头信息，用以模拟浏览器访问
user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
headers = {
'Connection': 'Keep-Alive',
'Accept': 'text/html, application/xhtml+xml, */*',
'Accept-Language': 'en-US,en;q=0.8,zh-Hans-CN;q=0.5,zh-Hans;q=0.3',
'User-Agent': 'Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko'
}
j=0
for i in range(1,30+1):
try:
#实现翻页翻页
        url = re.sub('page/\d+','page/%d'%i,url,re.S)
        print(url)
#发送请求，获得返回信息
        req = urllib.request.Request(url,headers=headers)
        response = urllib.request.urlopen(req,timeout=15)
        content = response.read().decode('utf-8')
#处理获取的web网页，并将信息处理了
        items1 = re.findall('<div class="article block untagged mb15" id=(.*?)<div class="stats"',content,re.S)

for i in items1:
# 多次使用正则表达式，运用先抓大再抓小原则。成功抓取纯净的图片地址
            items2 = re.findall('<div class="thumb">(.*?)</div>',i,re.S)
            picurl = re.findall('<img src=\"(.*?)\"',items2[0],re.S)
            print(picurl[0])
            pic = urllib.request.urlopen(picurl[0])
            jpgpic = pic.read()
# 打开文件，如果是windows pic后用\linux用/
            fp = open('pic/'+str(j)+'.jpg',"wb")
            print(j)
# 写入文件
            fp.write(jpgpic)
            fp.close()
            j=j+1
except HTTPError as e:
           print("HTTPError")
pass
except URLError as e:
        print("URLError")
pass
except:
pass