encoders.py

# Copyright (C) 2001-2006 Python Software Foundation
# Author: Barry Warsaw
# Contact: email-sig@python.org

"""Encodings and related functions."""

__all__= [
'encode_7or8bit',
'encode_base64',
'encode_noop',
'encode_quopri',
 ]


frombase64importencodebytesas_bencode
fromquopriimportencodestringas_encodestring


def_qencode(s):
enc=_encodestring(s, quotetabs=True)
# Must encode spaces, which quopri.encodestring() doesn't do
returnenc.replace(b' ', b'=20')


defencode_base64(msg):
"""Encode the message's payload in Base64.

 Also, add an appropriate Content-Transfer-Encoding header.
 """
orig=msg.get_payload(decode=True)
encdata=str(_bencode(orig), 'ascii')
msg.set_payload(encdata)
msg['Content-Transfer-Encoding'] ='base64'


defencode_quopri(msg):
"""Encode the message's payload in quoted-printable.

 Also, add an appropriate Content-Transfer-Encoding header.
 """
orig=msg.get_payload(decode=True)
encdata=_qencode(orig)
msg.set_payload(encdata)
msg['Content-Transfer-Encoding'] ='quoted-printable'


defencode_7or8bit(msg):
"""Set the Content-Transfer-Encoding header to 7bit or 8bit."""
orig=msg.get_payload(decode=True)
iforigisNone:
# There's no payload. For backwards compatibility we use 7bit
msg['Content-Transfer-Encoding'] ='7bit'
return
# We play a trick to make this go fast. If decoding from ASCII succeeds,
# we know the data must be 7bit, otherwise treat it as 8bit.
try:
orig.decode('ascii')
exceptUnicodeError:
msg['Content-Transfer-Encoding'] ='8bit'
else:
msg['Content-Transfer-Encoding'] ='7bit'


defencode_noop(msg):
"""Do nothing."""