通过 MIMEBase 发送 csv 文件作为附件 - python

Question

我不明白。我尝试发送带有 csv 文件作为附件的电子邮件。脚本的第一次运行很好，我收到了带有 csv 文件作为附件的电子邮件。但是在运行一次之后，脚本会崩溃并显示一条奇怪的 Traceback 消息。

到目前为止，这是我的代码：

import smtplib
import email.utils
from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase
from email.mime.text import MIMEText
from email import Encoders

msg = MIMEMultipart('foo')
msg['To'] = email.utils.formataddr(('foo', 'foo@foobar.de'))
msg['From'] = email.utils.formataddr(('foo', 'foo@foo'))
msg['Subject'] = 'foo'

# Attach a file

mail_file = file('foo.csv').read()

mail_file = MIMEBase('application', 'csv')
mail_file.set_payload(mail_file)
mail_file.add_header('Content-Disposition', 'attachment', filename='foo.csv')
Encoders.encode_base64(mail_file)
msg.attach(mail_file)

# Define SMTP server

server = smtplib.SMTP('localhost')
server.set_debuglevel(True) # show communication with the server

# Send the mail

try:
    server.sendmail('foo@foo', ['foo@foobar.de'], msg.as_string())
finally:
    server.quit()

现在我得到以下回溯：

Traceback (most recent call last):
File "mail.py", line 27, in <module>
    Encoders.encode_base64(mail_file)
File "/usr/lib/python2.7/email/encoders.py", line 45, in encode_base64
    encdata = _bencode(orig)
File "/usr/lib/python2.7/email/encoders.py", line 31, in _bencode
    hasnewline = (s[-1] == '\n')
File "/usr/lib/python2.7/email/message.py", line 294, in __getitem__
    return self.get(name)
File "/usr/lib/python2.7/email/message.py", line 360, in get
    name = name.lower()
AttributeError: 'int' object has no attribute 'lower'

当我取消注释第 27 行（编码行）时，我得到以下信息：

Traceback (most recent call last):
File "mail.py", line 33, in <module>
  server.sendmail('foo@foo', ['foo@foobar.de'], msg.as_string())

File "/usr/lib/python2.7/email/message.py", line 137, in as_string
  g.flatten(self, unixfrom=unixfrom)
File "/usr/lib/python2.7/email/generator.py", line 83, in flatten
  self._write(msg)
File "/usr/lib/python2.7/email/generator.py", line 108, in _write
  self._dispatch(msg)
File "/usr/lib/python2.7/email/generator.py", line 134, in _dispatch
  meth(msg)
File "/usr/lib/python2.7/email/generator.py", line 203, in _handle_multipart
  g.flatten(part, unixfrom=False)
File "/usr/lib/python2.7/email/generator.py", line 83, in flatten
  self._write(msg)
File "/usr/lib/python2.7/email/generator.py", line 108, in _write
  self._dispatch(msg)
File "/usr/lib/python2.7/email/generator.py", line 134, in _dispatch
  meth(msg)

File "/usr/lib/python2.7/email/generator.py", line 177, in _handle_text
  raise TypeError('string payload expected: %s' % type(payload))
TypeError: string payload expected: <type 'instance'>

有什么想法吗？

Answer 1

奇怪，当我这样做时

mail_file.set_payload(open('foo.csv', 'rb').read())

而不是

mail_file = file('foo.csv').read()
mail_file.set_payload(mail_file)

代码有效.. 仍然想知道为什么...！？