在python中解码utf-8电子邮件附件文件名？

Question

我收到一封带有附件名称的电子邮件，看起来像：

=?UTF-8?b?cmVhbF9hdHRhY2htZW50X25hbWUueGxz?=

但是，如果我查看Gmail中的原始文件，它将显示如下：

------=_Part_1264195_253682143.1529181492460
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="real_attachment_name.xls"


------=_Part_1264195_253682143.1529181492460--

如何获得真实的附件名称？

Answer 1

发生这种情况是因为没有预想到电子邮件会提供utf-8支持，所以已经有所了解。这里发生的是Content-Transfer-Encoding标头告诉您正在执行一些base64操作，您需要解码文件名，如下所示：

for part in mail.walk():
    if part.get_content_maintype() == 'multipart' or part.get('Content-Disposition') is None:
        continue

    filename = part.get_filename()

    # Find non-ascii filenames and decode

    transfer_encoding = part.get_all('Content-Transfer-Encoding')
    if transfer_encoding and transfer_encoding[0] == 'base64':
        filename_parts = filename.split('?')
        filename = base64.b64decode(filename_parts[3]).decode(filename_parts[1])