求助大神，网络爬虫问题

import urllib.request
import re
import os
def open_url(url):
req=urllib.request.Request(url)
req.add_header('User-Agent','Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.81 Mobile Safari/537.36')
response=urllib.request.urlopen(req)
html=response.read().decode('utf-8')
return html
def get_img(html):
reg=r'<img class="BDE_Image" pic_type="0" width="560" height="560" src="([^"]+\.jpg)"'
imglist=re.findall(reg,html)
print(imglist) / /这里返回空列表没有值求解
'''
print("一共有")
print(len(imglist))
for each in imglist:
print(each)
print("yes!")
for each in imglist:
filename = each.split("/")[-1]
urllib.request.urlretrieve(each,filename,None)
'''
if __name__=='__main__':
url='https://tieba.baidu.com/p/6216578674'
get_img(open_url(url))
最后返回的imglist没有返回值，是个空列表，求解啊