email 8bit encoding

[Antoon Pardon]

Op 01-08-13 17:20, rurpy at yahoo.com schreef:
> On 07/29/2013 02:52 PM, Antoon Pardon wrote:
>> Op 29-07-13 01:41, rurpy at yahoo.com schreef:
>>> How, using Python-3.3's email module, do I "flatten" (I think
>>> that's the right term) a Message object to get utf-8 encoded
>>> body with the headers:
>>>   Content-Type: text/plain; charset=UTF-8
>>>   Content-Transfer-Encoding: 8bit
>>> when the message payload was set to a python (unicode) string?
>>>
>>
>> I am just trying out some things for my self on python 3.2 so
>> be sure to test this out but you could try the following.
>>
>> msg.set_charset('utf-8')
>> msg['Content-Transfer-Encoding'] = '8bit'
> 
> You can do that but the problem occurs when you call 
> email.generator.flatten (or it is called on your behalf by 
> somthing like smtplib.send_message) with such a message.  
> flatten always assumes a 7bit encoding and uses the ascii 
> codec to encode the message resulting in a UnicodeEncode 
> exception when it hits an 8 bit character.  So gymnastics 
> like W. Trevor King implemented are necessary.

This works too, but I don't know how usefull it is with
multipart messages.

import smtplib
import os
import io

from email.mime.text import MIMEText
from email.generator import BytesGenerator

from email.generator import BytesGenerator

class EncodeGenerator(BytesGenerator):

    def flatten(self, msg, unixfrom=False, linesep='\n'):
        self._encoding = str(msg.get_charset())
        super().flatten(msg, unixfrom, linesep)

    def write(self, s):
        self._fp.write(s.encode(self._encoding))

    def _encode(self, s):
        return s.encode(self._encoding)


txt = '''\
Het adres is

Fréderic Boëven
Frère Orbanstraat 17
'''

recipient = " ... "
sender = " ... "

msg = MIMEText(txt)
msg.set_charset("utf-8")

msg['Subject'] = 'Python email test: %d' % os.getpid()
msg['From'] = sender
msg['To'] = recipient

print(msg['Subject'])

# Send the message via our own SMTP server.
s = smtplib.SMTP('localhost')

with io.BytesIO() as bytesmsg:
    g = EncodeGenerator(bytesmsg)
    g.flatten(msg, linesep='\r\n')
    flat_msg = bytesmsg.getvalue()

print(flat_msg)
s.sendmail(sender, [recipient], flat_msg)
s.quit()