jpayne@69: # Copyright (C) 2001-2006 Python Software Foundation
jpayne@69: # Author: Barry Warsaw
jpayne@69: # Contact: email-sig@python.org
jpayne@69: 
jpayne@69: """Encodings and related functions."""
jpayne@69: 
jpayne@69: __all__ = [
jpayne@69:     'encode_7or8bit',
jpayne@69:     'encode_base64',
jpayne@69:     'encode_noop',
jpayne@69:     'encode_quopri',
jpayne@69:     ]
jpayne@69: 
jpayne@69: 
jpayne@69: from base64 import encodebytes as _bencode
jpayne@69: from quopri import encodestring as _encodestring
jpayne@69: 
jpayne@69: 
jpayne@69: 
jpayne@69: def _qencode(s):
jpayne@69:     enc = _encodestring(s, quotetabs=True)
jpayne@69:     # Must encode spaces, which quopri.encodestring() doesn't do
jpayne@69:     return enc.replace(b' ', b'=20')
jpayne@69: 
jpayne@69: 
jpayne@69: def encode_base64(msg):
jpayne@69:     """Encode the message's payload in Base64.
jpayne@69: 
jpayne@69:     Also, add an appropriate Content-Transfer-Encoding header.
jpayne@69:     """
jpayne@69:     orig = msg.get_payload(decode=True)
jpayne@69:     encdata = str(_bencode(orig), 'ascii')
jpayne@69:     msg.set_payload(encdata)
jpayne@69:     msg['Content-Transfer-Encoding'] = 'base64'
jpayne@69: 
jpayne@69: 
jpayne@69: 
jpayne@69: def encode_quopri(msg):
jpayne@69:     """Encode the message's payload in quoted-printable.
jpayne@69: 
jpayne@69:     Also, add an appropriate Content-Transfer-Encoding header.
jpayne@69:     """
jpayne@69:     orig = msg.get_payload(decode=True)
jpayne@69:     encdata = _qencode(orig)
jpayne@69:     msg.set_payload(encdata)
jpayne@69:     msg['Content-Transfer-Encoding'] = 'quoted-printable'
jpayne@69: 
jpayne@69: 
jpayne@69: 
jpayne@69: def encode_7or8bit(msg):
jpayne@69:     """Set the Content-Transfer-Encoding header to 7bit or 8bit."""
jpayne@69:     orig = msg.get_payload(decode=True)
jpayne@69:     if orig is None:
jpayne@69:         # There's no payload.  For backwards compatibility we use 7bit
jpayne@69:         msg['Content-Transfer-Encoding'] = '7bit'
jpayne@69:         return
jpayne@69:     # We play a trick to make this go fast.  If decoding from ASCII succeeds,
jpayne@69:     # we know the data must be 7bit, otherwise treat it as 8bit.
jpayne@69:     try:
jpayne@69:         orig.decode('ascii')
jpayne@69:     except UnicodeError:
jpayne@69:         msg['Content-Transfer-Encoding'] = '8bit'
jpayne@69:     else:
jpayne@69:         msg['Content-Transfer-Encoding'] = '7bit'
jpayne@69: 
jpayne@69: 
jpayne@69: 
jpayne@69: def encode_noop(msg):
jpayne@69:     """Do nothing."""