【Pyton】【小甲鱼】爬虫4-XXOO

import urllib.request
import os

def open_url(url):
    req=urllib.request.Request(url)
    req.add_header('User-Agent','Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36')
    response=urllib.request.urlopen(url)
    html=response.read()

    print(url)
    return html

def get_page(url):
    html=open_url(url).decode('utf-8')
    
    a=html.find('current-comment-page')+23 #23代表偏移
    b=html.find(']',a) #a代表起始位置
    return html[a:b]
    
def find_imgs(url):
    html=open_url(url).decode('utf-8')
    img_addrs=[]
   #图片的左右边界
    a=html.find('img src=')
    while a!=-1:
        b=html.find('.jpg',a,a+255)
        if b!=-1:
            img_addrs.append(html[a+9:b+4])
        else:
            b=a+9
        a=html.find('img src=',b)
   
    for each in img_addrs:
        print(each)
    return img_addrs

def save_imgs(folder,img_addrs):
    for each in img_addrs:
        filename=each.split('/')[-1]
        with open(filename,'wb')as f:
            img=open_url(each)
            f.write(img)

def download_mm(folder='OOXX',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=str('http')+find_imgs(page_url)
        save_imgs(folder,img_addrs)

if __name__=='__main__':
    download_mm()