电子邮件中的附件变成了“noname”

Question

我尝试使用 python 发送电子邮件并放置附件，但是当它发送时，附件变成了没有任何扩展名的 noname。

message = MIMEMultipart()
message ['From'] = sender_email
message ['To'] = ', '.join(receiver_email)
message ['Subject'] = 'Python Email'
message.attach(MIMEText(mail_content, 'plain'))
attach_file_name = 'Final Project - Basic Python.pdf'
attach_file = open('Final Project - Basic Python.pdf', 'rb')
payload = MIMEBase('application', 'octate-stream')
payload.set_payload((attach_file).read())
encoders.encode_base64(payload)
payload.add_header('Content-Decomposition', 'attachment', filename=attach_file_name)
message.attach(payload)