cpython/Lib/email/Utils.py

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# Copyright (C) 2001 Python Software Foundation
# Author: barry@zope.com (Barry Warsaw)
"""Miscellaneous utilities.
"""
import time
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
from quopri import decodestring as _qdecode
import base64
# Intrapackage imports
from Encoders import _bencode, _qencode
COMMASPACE = ', '
UEMPTYSTRING = u''
# 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
def getaddresses(fieldvalues):
"""Return a list of (REALNAME, EMAIL) for each fieldvalue."""
all = COMMASPACE.join(fieldvalues)
a = _AddrlistClass(all)
return a.getaddrlist()
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)
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)
def formatdate(timeval=None, localtime=0):
"""Returns a date string as specified by RFC 2822, e.g.:
Fri, 09 Nov 2001 01:08:47 -0000
Optional timeval if given is a floating point time value as accepted by
gmtime() and localtime(), otherwise the current time is used.
Optional localtime is a flag that when true, interprets timeval, and
returns a date relative to the local timezone instead of UTC, properly
taking daylight savings time into account.
"""
# Note: we cannot use strftime() because that honors the locale and RFC
# 2822 requires that day and month names be the English abbreviations.
if timeval is None:
timeval = time.time()
if localtime:
now = time.localtime(timeval)
# Calculate timezone offset, based on whether the local zone has
# daylight savings time, and whether DST is in effect.
if time.daylight and now[-1]:
offset = time.altzone
else:
offset = time.timezone
hours, minutes = divmod(abs(offset), 3600)
# Remember offset is in seconds west of UTC, but the timezone is in
# minutes east of UTC, so the signs differ.
if offset > 0:
sign = '-'
else:
sign = '+'
zone = '%s%02d%02d' % (sign, hours, minutes / 60)
else:
now = time.gmtime(timeval)
# Timezone offset is always -0000
zone = '-0000'
return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][now[6]],
now[2],
['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][now[1] - 1],
now[0], now[3], now[4], now[5],
zone)