# 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', | |
] | |
import base64 | |
from quopri import encodestring as _encodestring | |
def _qencode(s): | |
enc = _encodestring(s, quotetabs=True) | |
# Must encode spaces, which quopri.encodestring() doesn't do | |
return enc.replace(' ', '=20') | |
def _bencode(s): | |
# We can't quite use base64.encodestring() since it tacks on a "courtesy | |
# newline". Blech! | |
if not s: | |
return s | |
hasnewline = (s[-1] == '\n') | |
value = base64.encodestring(s) | |
if not hasnewline and value[-1] == '\n': | |
return value[:-1] | |
return value | |
def encode_base64(msg): | |
"""Encode the message's payload in Base64. | |
Also, add an appropriate Content-Transfer-Encoding header. | |
""" | |
orig = msg.get_payload() | |
encdata = _bencode(orig) | |
msg.set_payload(encdata) | |
msg['Content-Transfer-Encoding'] = 'base64' | |
def encode_quopri(msg): | |
"""Encode the message's payload in quoted-printable. | |
Also, add an appropriate Content-Transfer-Encoding header. | |
""" | |
orig = msg.get_payload() | |
encdata = _qencode(orig) | |
msg.set_payload(encdata) | |
msg['Content-Transfer-Encoding'] = 'quoted-printable' | |
def encode_7or8bit(msg): | |
"""Set the Content-Transfer-Encoding header to 7bit or 8bit.""" | |
orig = msg.get_payload() | |
if orig is None: | |
# 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 encoding to ASCII succeeds, we | |
# know the data must be 7bit, otherwise treat it as 8bit. | |
try: | |
orig.encode('ascii') | |
except UnicodeError: | |
msg['Content-Transfer-Encoding'] = '8bit' | |
else: | |
msg['Content-Transfer-Encoding'] = '7bit' | |
def encode_noop(msg): | |
"""Do nothing.""" |