Send csv-file as attachment via MIMEBase - python - email

Question

I don't get it. I try to send an e-mail with a csv-file as attachment. The first run with the script was fine, I recieved the e-mail with the csv-file as attachment. But after running it once, the script crashes with an odd Traceback message.
Heres my code so far:
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()
Now I get the following traceback:
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'
When I uncomment line 27 (Encoding Line), I get the following:
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'>
Any ideas?

Answer 1

Strange, when I do
mail_file.set_payload(open('foo.csv', 'rb').read())
instead of
mail_file = file('foo.csv').read()
mail_file.set_payload(mail_file)
the Code works.. Still wondering why...!?