解决网页采集编码正确还是报错的问题

url = 'https://pic.netbian.com/tupian/24072.html'
res = requests.get(url=url)
if '<meta charset="gbk"' in str(res.content):
    cont = res.content.decode('gbk',errors='ignore')
else:
    cont = res.content.decode('gb18030',errors='ignore')