自己做的一个下载图片的爬虫，说是编码问题但是我找不出来，求教

Question

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; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.221 Safari/537.36 SE 2.X MetaSr 1.0')

    response = urllib.request.urlopen(url)

    html = response.read()

    return html

    

def get_page(url):

    html = url_open(url).decode('utf-8')

    

    a = html.find('thisclass') + 12

    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 sava_imgs(folder,img_addrs):

    for each in img_addrs:

        filename = each.split('/')[-1]

        print(filename)

        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://www.meizitu.com/a/'

    page_num = int(get_page(url))

    

    for i in range(pages):

        page_num -= i

        page_url = url  + 'more_' + str(page_num) + '.html'

        img_addrs = find_imgs(page_url)

        sava_imgs(folder,img_addrs)

        

if __name__ == '__main__':

    download_mm()         

报错是这样的：UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc3 in position 255: invalid continuation byte