“str”对象没有“decode”属性。Python 3错误呢?

Here is my code:

这是我的代码:

import imaplib
from email.parser import HeaderParser

conn = imaplib.IMAP4_SSL('imap.gmail.com')
conn.login('[email protected]', 'password')
conn.select()
conn.search(None, 'ALL')
data = conn.fetch('1', '(BODY[HEADER])')
header_data = data[1][0][1].decode('utf-8')
import imaplib
fro