Gmail和Python，使用相同附件发送不同电子邮件

Question

我需要发送多封电子邮件（如每天200封定制电子邮件），但都有相同的pdf附件。是否可以只上传一次附件以节省上传时间？ 甚至比这更好的是，是否有可能只在google服务器上上传一次文件，每天只引用该文件？在

以下代码仅供参考（修改自google developer示例代码）：

# main function 
def SendMessageAttachment(sender, to, subject, msgHtml, msgPlain, attachmentFile):
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('gmail', 'v1', http=http)
    message1 = create_message_with_attachment(sender, to, subject, msgPlain, attachmentFile)
    SendMessageInternal(service, "me", message1)

def SendMessageInternal(service, user_id, message):
    try:
        message = (service.users().messages().send(userId=user_id, body=message).execute())
        print 'Message Id: %s' % message['id']
        return message
    except errors.HttpError, error:
        print 'An error occurred: %s' % error


def create_message_with_attachment(
    sender, to, subject, message_text, attachmentFile):
    """Create a message for an email.

    Args:
      sender: Email address of the sender.
      to: Email address of the receiver.
      subject: The subject of the email message.
      message_text: The text of the email message.
      file: The path to the file to be attached.

    Returns:
      An object containing a base64url encoded email object.
    """
    message = MIMEMultipart()
    message['to'] = to
    message['from'] = sender
    message['subject'] = subject

    msg = MIMEText(message_text)
    message.attach(msg)

    print "create_message_with_attachment: file:", attachmentFile
    content_type, encoding = mimetypes.guess_type(attachmentFile)

    if content_type is None or encoding is not None:
        content_type = 'application/octet-stream'
    main_type, sub_type = content_type.split('/', 1)
    if main_type == 'text':
        fp = open(attachmentFile, 'rb')
        msg = MIMEText(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'image':
        fp = open(attachmentFile, 'rb')
        msg = MIMEImage(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'audio':
        fp = open(attachmentFile, 'rb')
        msg = MIMEAudio(fp.read(), _subtype=sub_type)
        fp.close()
    else:
        fp = open(attachmentFile, 'rb')
        msg = MIMEBase(main_type, sub_type)
        msg.set_payload(fp.read())
        fp.close()
    filename = os.path.basename(attachmentFile)
    msg.add_header('Content-Disposition', 'attachment', filename=filename)
    message.attach(msg)

    return {'raw': base64.urlsafe_b64encode(message.as_string())}

Answer 1

附件加载在此处：

part = MIMEApplication(open("mypdf.pdf","rb").read())

但是头的引用可以是任何地方

^{pr2}$

您可以编写一个函数来在发送邮件之前添加这个头，并遍历所有收件人。在