附件包含UTF8字符时Python imaplib get_filename（）不工作

Question

我有这个功能，可以使用imaplib从给定的电子邮件下载所有附件

# Download all attachment files for a given email
def downloaAttachmentsInEmail(m, emailid, outputdir, markRead):
    resp, data = m.uid("FETCH", emailid, "(BODY.PEEK[])")
    email_body = data[0][1]
    mail = email.message_from_bytes(email_body)
    if mail.get_content_maintype() != 'multipart':
        return
    for part in mail.walk():
        if part.get_content_maintype() != 'multipart' and part.get('Content-Disposition') is not None:
            open(outputdir + '/' + part.get_filename(), 'wb').write(part.get_payload(decode=True)
    if(markRead):
        m.uid("STORE", emailid, "+FLAGS", "(\Seen)")

问题是，当我尝试下载文件名中包含UTF-8字符的文件时，它不起作用。我得到了这个错误，我想这是因为part.get\u filename（）没有正确读取名称：

    OSError: [Errno 22] Invalid argument: './temp//=?UTF-8?B?QkQgUmVsYXTDs3JpbyAywqogRmFzZS5kb2M=?=\r\n\t=?UTF-8?B?eA==?='

我能做些什么来解决这个问题

Answer 1

我找到了解决办法

# Download all attachment files for a given email
def downloaAttachmentsInEmail(m, emailid, outputdir, markRead):
    resp, data = m.uid("FETCH", emailid, "(BODY.PEEK[])")
    email_body = data[0][1]
    mail = email.message_from_bytes(email_body)
    if mail.get_content_maintype() != 'multipart':
        return
    for part in mail.walk():
        if part.get_content_maintype() != 'multipart' and part.get('Content-Disposition') is not None:
            filename, encoding = decode_header(part.get_filename())[0]
            if(encoding is None):
                open(outputdir + '/' + filename, 'wb').write(part.get_payload(decode=True))
            else:
                open(outputdir + '/' + filename.decode(encoding), 'wb').write(part.get_payload(decode=True))
    if(markRead):
        m.uid("STORE", emailid, "+FLAGS", "(\Seen)")**

Answer 2

这是一个老问题，但我面对这个问题，很难找到解决办法。。。也许这可以帮助其他人

编辑：这仅包括将文件名“解码”为正确文件名的部分

import re
import base64
import quopri

def encoded_words_to_text(encoded_words):
    try:
        encoded_word_regex = r'=\?{1}(.+)\?{1}([B|Q])\?{1}(.+)\?{1}='
        charset, encoding, encoded_text = re.match(encoded_word_regex, encoded_words).groups()
        if encoding is 'B':
            byte_string = base64.b64decode(encoded_text)
        elif encoding is 'Q':
            byte_string = quopri.decodestring(encoded_text)
        return byte_string.decode(charset)
    except:
        return encoded_words

结果:

test_string = '=?utf-8?B?SUJUIFB1cmNoYXNlIE9yZGVyLnBkZg==?='
encoded_words_to_text(test_string)
'IBT Purchase Order.pdf'