Use Python3 to write scripts that crawl Web pages and capture only web images

The most basic code to crawl Web content is implemented:

#!/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__ ':   

Use the Urllib module to implement a Web page that captures the image:

Import urllib.request Import socket import re import sys import OS TargetDir = R "C:\Users\elqstux\Desktop\pic" Def Destfil E (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, the T in Set (Re.findall (R ' (http:[^\s]*) ( jpg|png|gif)) ', str (contentbytes)):     print (link)     

import urllib.request import socket import re import sys import OS TargetDir = R "H:\pic" Def Destfi Le (path): If not Os.path.isdir (TargetDir): Os.mkdir (targetDir) pos = Path.rindex ('/') T = Os.path.join (TargetDir , path[pos+1:]) #会以/As separate return t if __name__ = = "__main__": hostname = "http://www.douban.com/" req = Urllib.reque St. 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) ' contains two layers of parentheses, so there are two groupings, #上面会返回列表, the matching contents in parentheses will appear in the list for Picname, Pictype in match: Print (picname) print (pictype) "Output: Http://img3.douban.com/pics/blank.gif gif http://img3.douban.com/icon/g1 11328-1.jpg jpg http://img3.douban.com/pics/blank.gif gif http://img3.douban.com/icon/g197523-19.jpg jpg/http/ Img3.douban.com/pics/blank.gif gif ... ''' 

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