import sys
import io
sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='utf-8')
url = 'http://comment.bilibili.com/34568185.xml'
r = requests.get(url)
print(r.content.decode('utf-8'))
r.content返回的是bytes
r.text 返回的是bytes解码后的字符串，自动解码就可能解错