#!/usr/bin/env python 
 
from urllib import urlretrieve 
 
def firstNonBlank(lines): 
 for eachLine in lines: 
 if not eachLine.strip(): 
 continue 
 else: 
 return eachLine 
 
def firstLast(webpage): 
 f = open(webpage) 
 lines = f.readlines() 
 f.close() 
 print firstNonBlank(lines), 
 lines.reverse() 
 print firstNonBlank(lines), 
 
def download(url='http://www',process=firstLast): 
 try: 
 retval = urlretrieve(url)[0] 
 except IOError: 
 retval = None 
 if retval: 
 process(retval) 
 
if __name__ == '__main__': 
 download() 

利用urllib模块，来实现一个网页中针对图片的抓取功能：

import urllib.request 
import socket 
import re 
import sys 
import os 
targetDir = r"C:UserselqstuxDesktoppic" 
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 
 
if __name__ == "__main__": 
 hostname = "http://www.douban.com" 
 req = urllib.request.Request(hostname) 
 webpage = urllib.request.urlopen(req) 
 contentBytes = webpage.read() 
 for link, t in set(re.findall(r'(http:[^s]*?(jpg|png|gif))', str(contentBytes))): 
 print(link) 
 urllib.request.urlretrieve(link, destFile(link)) 

import urllib.request 
import socket 
import re 
import sys 
import os 
targetDir = r"H:pic" 
def destFile(path): 
 if not os.path.isdir(targetDir): 
 os.mkdir(targetDir) 
 pos = path.rindex('/') 
 t = os.path.join(targetDir, path[pos+1:]) #会以/作为分隔 
 return t 
 
if __name__ == "__main__": 
 hostname = "http://www.douban.com/" 
 req = urllib.request.Request(hostname) 
 webpage = urllib.request.urlopen(req) 
 contentBytes = webpage.read() 
 match = re.findall(r'(http:[^s]*?(jpg|png|gif))', str(contentBytes) )#r'(http:[^s]*?(jpg|png|gif))'中包含两层圆括号，故有两个分组， 
 #上面会返回列表，括号中匹配的内容才会出现在列表中 
 for picname, picType in match: 
 print(picname) 
 print(picType) 
 
 
'''''