Python爬虫获取图片并下载保存至本地

import urllib.request

import os

#to open the url

def url_open(url):

 req=urllib.request.Request(url)

 req.add_header('User-Agent','Mozilla/5.0 (Windows NT 6.3; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0')

 response=urllib.request.urlopen(url)

 html=response.read()

 return html

#to get the num of page like 1,2,3,4...

def get_page(url):

 html=url_open(url).decode('utf-8')

 a=html.find('current-comment-page')+23 #add the 23 offset th arrive at the [2356]

 b=html.find(']',a)

 #print(html[a:b])

 return html[a:b]

#find the url of imgs and return the url of arr

def find_imgs(url):

 html=url_open(url).decode('utf-8')

 img_addrs=[]

 a=html.find('img src=')

 while a!=-1:

  b=html.find('.jpg',a,a+255) # if false : return -1

  if b!=-1:

   img_addrs.append('http:'+html[a+9:b+4])

  else:

   b=a+9

  a=html.find('img src=',b)

 #print(img_addrs) 

 return img_addrs

  #print('http:'+each)

   

#save the imgs

def save_imgs(folder,img_addrs):

 for each in img_addrs:

  filename=each.split('/')[-1] #get the last member of arr,that is the name

  with open(filename,'wb') as f:

   img = url_open(each)

   f.write(img)

  

def download_mm(folder='mm',pages=10):

 os.mkdir(folder)

 os.chdir(folder)

 url='http://jandan.net/ooxx/'

 page_num=int(get_page(url))

  

 for i in range(pages):

  page_num -= i

  page_url = url + 'page-' + str(page_num) + '#comments'

  img_addrs=find_imgs(page_url)

  save_imgs(folder,img_addrs)

   

if __name__ == '__main__':

 download_mm()