cpython/Lib/email/Utils.py

105 lines
2.8 KiB
Python
Raw Normal View History

# Copyright (C) 2001 Python Software Foundation
# Author: barry@zope.com (Barry Warsaw)
"""Miscellaneous utilities.
"""
import re
from rfc822 import unquote, quote, parseaddr
from rfc822 import dump_address_pair
from rfc822 import AddrlistClass as _AddrlistClass
from rfc822 import parsedate_tz, parsedate, mktime_tz, formatdate
from quopri import decodestring as _qdecode
import base64
# Intrapackage imports
from Encoders import _bencode, _qencode
COMMASPACE = ', '
UEMPTYSTRING = u''
2001-10-04 14:05:11 -03:00
# Helpers
def _identity(s):
return s
def _bdecode(s):
if not s:
return 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.decodestring(s)
if not hasnewline and value[-1] == '\n':
return value[:-1]
return value
2001-10-04 14:05:11 -03:00
def getaddresses(fieldvalues):
"""Return a list of (REALNAME, EMAIL) for each fieldvalue."""
all = COMMASPACE.join(fieldvalues)
a = _AddrlistClass(all)
return a.getaddrlist()
2001-10-04 14:05:11 -03:00
ecre = re.compile(r'''
=\? # literal =?
(?P<charset>[^?]*?) # non-greedy up to the next ? is the charset
\? # literal ?
(?P<encoding>[qb]) # either a "q" or a "b", case insensitive
\? # literal ?
(?P<atom>.*?) # non-greedy up to the next ?= is the atom
\?= # literal ?=
''', re.VERBOSE | re.IGNORECASE)
def decode(s):
"""Return a decoded string according to RFC 2047, as a unicode string."""
rtn = []
parts = ecre.split(s, 1)
while parts:
# If there are less than 4 parts, it can't be encoded and we're done
if len(parts) < 5:
rtn.extend(parts)
break
# The first element is any non-encoded leading text
rtn.append(parts[0])
charset = parts[1]
encoding = parts[2]
atom = parts[3]
# The next chunk to decode should be in parts[4]
parts = ecre.split(parts[4])
# The encoding must be either `q' or `b', case-insensitive
if encoding.lower() == 'q':
func = _qdecode
elif encoding.lower() == 'b':
func = _bdecode
else:
func = _identity
# Decode and get the unicode in the charset
rtn.append(unicode(func(atom), charset))
# Now that we've decoded everything, we just need to join all the parts
# together into the final string.
return UEMPTYSTRING.join(rtn)
2001-10-04 14:05:11 -03:00
def encode(s, charset='iso-8859-1', encoding='q'):
"""Encode a string according to RFC 2047."""
if encoding.lower() == 'q':
estr = _qencode(s)
elif encoding.lower() == 'b':
estr = _bencode(s)
else:
raise ValueError, 'Illegal encoding code: ' + encoding
return '=?%s?%s?%s?=' % (charset.lower(), encoding.lower(), estr)