09-downPicture.py

'''
爬取某个网页上的所有图片资源

'''
import urllib.request
import socket
import re
import sys
import os

targetDir = r'result\09-downPicture'    #文件保存路径  

def destFile(path):
    if not os.path.isdir(targetDir):
        os.mkdir(targetDir)
    pos = path.rindex('/')
    t = os.path.join(targetDir, path[pos+1:])
    return t

def downPicture(weburl):
    webheaders = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0'}   
    req = urllib.request.Request(url=weburl, headers=webheaders)    #构造请求报头  
    webpage = urllib.request.urlopen(req)   #发送请求报头  
    contentBytes = webpage.read()
    for link,t in set(re.findall(r'(http:[^\s]*?(jpg|png|gif))', str(contentBytes))):   #正则表达式查找所有的图片
        print(link)
        try:
            urllib.request.urlretrieve(link, destFile(link))     #下载图片  
        except :
            print('失败')

if __name__ == '__main__':
    weburl = 'http://www.douban.com/'
    downPicture(weburl)