爬图错误，求大佬指教

雨天啊

程序是
import urllib.request
import os


def url_open(url):
   
    req=urllib.request.Request(url)
    req.add_header('User_Agent','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36')
    response=urllib.request.urlopen(url)
    html=response.read()
    return html

def get_page(url):
   
    html=url_open(url).decode('utf-8')
  
  
   
    a=html.find('current-comment-page')+23
    b=html.find(']',a)
    return html[a:b]

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 b !=-1:
            
            img_addrs.append(html[a+9:b+4])
           
        else:
            
            b=a+9
            
            
        a=html.find('img src=',b)
        
    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 = url_open(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=find_imgs(page_url)
        
            save_imgs(folder,img_addrs)


if __name__ == '__main__':

       download_mm()

        输入出现错误：
Traceback (most recent call last):
  File "C:\Users\雨天\Desktop\抓图.py", line 75, in <module>
    download_mm()
  File "C:\Users\雨天\Desktop\抓图.py", line 71, in download_mm
    save_imgs(folder,img_addrs)
  File "C:\Users\雨天\Desktop\抓图.py", line 52, in save_imgs
    img = url_open(each)
  File "C:\Users\雨天\Desktop\抓图.py", line 7, in url_open
    req=urllib.request.Request(url)
  File "C:\Users\雨天\AppData\Local\Programs\Python\Python37-32\lib\urllib\request.py", line 328, in __init__
    self.full_url = url
  File "C:\Users\雨天\AppData\Local\Programs\Python\Python37-32\lib\urllib\request.py", line 354, in full_url
    self._parse()
  File "C:\Users\雨天\AppData\Local\Programs\Python\Python37-32\lib\urllib\request.py", line 383, in _parse
    raise ValueError("unknown url type: %r" % self.full_url)
ValueError: unknown url type: '//wx3.sinaimg.cn/mw600/0076BSS5ly1g5gi25dgg7j30u0193wvs.jpg'
>>>

huangtt123

图片地址没加http？