Encode MIMEText as quoted printables

Question

Python supports a quite functional MIME-Library called email.mime.

What I want to achieve is to get a MIME Part containing plain UTF-8 text to be encod

Answer 1

You do not need your hack:

import email

# Construct a new charset which uses Quoted Printables (base64 is default)
cs = email.charset.Charset('utf-8')
cs.body_encoding = email.charset.QP

m = email.mime.text.MIMEText(u'This is the text containing ünicöde', 'plain', _charset=cs)

print(m.as_string())

Answer 2

Okay, I got one solution which is very hacky, but at least it leads into some direction: MIMEText assumes base64 and I don't know how to change this. For this reason I use MIMENonMultipart:

import email.mime, email.mime.nonmultipart, email.charset
m=email.mime.nonmultipart.MIMENonMultipart('text', 'plain', charset='utf-8')

#Construct a new charset which uses Quoted Printables (base64 is default)
cs=email.charset.Charset('utf-8')
cs.body_encoding = email.charset.QP

#Now set the content using the new charset
m.set_payload(u'This is the text containing ünicöde', charset=cs)

Now the message seems to be encoded correctly:

Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable

This is the text containing =C3=BCnic=C3=B6de

One can even construct a new class which hides the complexity:

class MIMEUTF8QPText(email.mime.nonmultipart.MIMENonMultipart):
  def __init__(self, payload):
    email.mime.nonmultipart.MIMENonMultipart.__init__(self, 'text', 'plain',
                                                      charset='utf-8')

    utf8qp=email.charset.Charset('utf-8')
    utf8qp.body_encoding=email.charset.QP

    self.set_payload(payload, charset=utf8qp) 

And use it like this:

m = MIMEUTF8QPText(u'This is the text containing ünicöde')
m.as_string()

Answer 3

Adapted from issue 1525919 and tested on python 2.7:

from email.Message import Message
from email.Charset import Charset, QP

text = "\xc3\xa1 = \xc3\xa9"
msg = Message()

charset = Charset('utf-8')
charset.header_encoding = QP
charset.body_encoding = QP

msg.set_charset(charset)
msg.set_payload(msg._charset.body_encode(text))

print msg.as_string()

will give you:

MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable

=C3=A1 =3D =C3=A9

Also see this response from a Python committer.