# 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', ] from base64 import encodebytes as _bencode 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(b' ', b'=20') def encode_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'  def encode_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'  def encode_7or8bit(msg): """Set the Content-Transfer-Encoding header to 7bit or 8bit.""" orig = msg.get_payload(decode=True) 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 decoding from ASCII succeeds, # we know the data must be 7bit, otherwise treat it as 8bit. try: orig.decode('ascii') except UnicodeError: msg['Content-Transfer-Encoding'] = '8bit' else: msg['Content-Transfer-Encoding'] = '7bit'  def encode_noop(msg): """Do nothing."""