[Python-checkins] cpython: #665194: support roundtripping RFC2822 date stamps in the email.utils module
r.david.murray
python-checkins at python.org
Wed Jul 20 17:41:43 CEST 2011
http://hg.python.org/cpython/rev/5f7b03dcd523
changeset: 71439:5f7b03dcd523
parent: 71437:bc71fff2b6c7
user: R David Murray <rdmurray at bitdance.com>
date: Wed Jul 20 11:41:21 2011 -0400
summary:
#665194: support roundtripping RFC2822 date stamps in the email.utils module
files:
Doc/library/email.util.rst | 28 +++++++++++
Lib/email/_parseaddr.py | 19 +++++++-
Lib/email/utils.py | 46 ++++++++++++++++--
Lib/test/test_email/test_utils.py | 45 ++++++++++++++++++
Misc/NEWS | 3 +
5 files changed, 133 insertions(+), 8 deletions(-)
diff --git a/Doc/library/email.util.rst b/Doc/library/email.util.rst
--- a/Doc/library/email.util.rst
+++ b/Doc/library/email.util.rst
@@ -81,6 +81,20 @@
indexes 6, 7, and 8 of the result tuple are not usable.
+.. function:: parsedate_to_datetime(date)
+
+ The inverse of :func:`format_datetime`. Performs the same function as
+ :func:`parsedate`, but on success returns a :mod:`~datetime.datetime`. If
+ the input date has a timezone of ``-0000``, the ``datetime`` will be a naive
+ ``datetime``, and if the date is conforming to the RFCs it will represent a
+ time in UTC but with no indication of the actual source timezone of the
+ message the date comes from. If the input date has any other valid timezone
+ offset, the ``datetime`` will be an aware ``datetime`` with the
+ corresponding a :class:`~datetime.timezone` :class:`~datetime.tzinfo`.
+
+ .. versionadded:: 3.3
+
+
.. function:: mktime_tz(tuple)
Turn a 10-tuple as returned by :func:`parsedate_tz` into a UTC timestamp. It
@@ -112,6 +126,20 @@
``False``. The default is ``False``.
+.. function:: format_datetime(dt, usegmt=False)
+
+ Like ``formatdate``, but the input is a :mod:`datetime` instance. If it is
+ a naive datetime, it is assumed to be "UTC with no information about the
+ source timezone", and the conventional ``-0000`` is used for the timezone.
+ If it is an aware ``datetime``, then the numeric timezone offset is used.
+ If it is an aware timezone with offset zero, then *usegmt* may be set to
+ ``True``, in which case the string ``GMT`` is used instead of the numeric
+ timezone offset. This provides a way to generate standards conformant HTTP
+ date headers.
+
+ .. versionadded:: 3.3
+
+
.. function:: make_msgid(idstring=None, domain=None)
Returns a string suitable for an :rfc:`2822`\ -compliant
diff --git a/Lib/email/_parseaddr.py b/Lib/email/_parseaddr.py
--- a/Lib/email/_parseaddr.py
+++ b/Lib/email/_parseaddr.py
@@ -47,6 +47,21 @@
Accounts for military timezones.
"""
+ res = _parsedate_tz(data)
+ if res[9] is None:
+ res[9] = 0
+ return tuple(res)
+
+def _parsedate_tz(data):
+ """Convert date to extended time tuple.
+
+ The last (additional) element is the time zone offset in seconds, except if
+ the timezone was specified as -0000. In that case the last element is
+ None. This indicates a UTC timestamp that explicitly declaims knowledge of
+ the source timezone, as opposed to a +0000 timestamp that indicates the
+ source timezone really was UTC.
+
+ """
data = data.split()
# The FWS after the comma after the day-of-week is optional, so search and
# adjust for this.
@@ -138,6 +153,8 @@
tzoffset = int(tz)
except ValueError:
pass
+ if tzoffset==0 and tz.startswith('-'):
+ tzoffset = None
# Convert a timezone offset into seconds ; -0500 -> -18000
if tzoffset:
if tzoffset < 0:
@@ -147,7 +164,7 @@
tzsign = 1
tzoffset = tzsign * ( (tzoffset//100)*3600 + (tzoffset % 100)*60)
# Daylight Saving Time flag is set to -1, since DST is unknown.
- return yy, mm, dd, thh, tmm, tss, 0, 1, -1, tzoffset
+ return [yy, mm, dd, thh, tmm, tss, 0, 1, -1, tzoffset]
def parsedate(data):
diff --git a/Lib/email/utils.py b/Lib/email/utils.py
--- a/Lib/email/utils.py
+++ b/Lib/email/utils.py
@@ -11,12 +11,14 @@
'encode_rfc2231',
'formataddr',
'formatdate',
+ 'format_datetime',
'getaddresses',
'make_msgid',
'mktime_tz',
'parseaddr',
'parsedate',
'parsedate_tz',
+ 'parsedate_to_datetime',
'unquote',
]
@@ -26,6 +28,7 @@
import base64
import random
import socket
+import datetime
import urllib.parse
import warnings
from io import StringIO
@@ -37,6 +40,7 @@
# We need wormarounds for bugs in these methods in older Pythons (see below)
from email._parseaddr import parsedate as _parsedate
from email._parseaddr import parsedate_tz as _parsedate_tz
+from email._parseaddr import _parsedate_tz as __parsedate_tz
from quopri import decodestring as _qdecode
@@ -110,6 +114,14 @@
''', re.VERBOSE | re.IGNORECASE)
+def _format_timetuple_and_zone(timetuple, zone):
+ return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
+ ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][timetuple[6]],
+ timetuple[2],
+ ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+ 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][timetuple[1] - 1],
+ timetuple[0], timetuple[3], timetuple[4], timetuple[5],
+ zone)
def formatdate(timeval=None, localtime=False, usegmt=False):
"""Returns a date string as specified by RFC 2822, e.g.:
@@ -154,14 +166,25 @@
zone = 'GMT'
else:
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)
+ return _format_timetuple_and_zone(now, zone)
+def format_datetime(dt, usegmt=False):
+ """Turn a datetime into a date string as specified in RFC 2822.
+
+ If usegmt is True, dt must be an aware datetime with an offset of zero. In
+ this case 'GMT' will be rendered instead of the normal +0000 required by
+ RFC2822. This is to support HTTP headers involving date stamps.
+ """
+ now = dt.timetuple()
+ if usegmt:
+ if dt.tzinfo is None or dt.tzinfo != datetime.timezone.utc:
+ raise ValueError("usegmt option requires a UTC datetime")
+ zone = 'GMT'
+ elif dt.tzinfo is None:
+ zone = '-0000'
+ else:
+ zone = dt.strftime("%z")
+ return _format_timetuple_and_zone(now, zone)
def make_msgid(idstring=None, domain=None):
@@ -203,6 +226,15 @@
return None
return _parsedate_tz(data)
+def parsedate_to_datetime(data):
+ if not data:
+ return None
+ *dtuple, tz = __parsedate_tz(data)
+ if tz is None:
+ return datetime.datetime(*dtuple[:6])
+ return datetime.datetime(*dtuple[:6],
+ tzinfo=datetime.timezone(datetime.timedelta(seconds=tz)))
+
def parseaddr(addr):
addrs = _AddressList(addr).addresslist
diff --git a/Lib/test/test_email/test_utils.py b/Lib/test/test_email/test_utils.py
new file mode 100644
--- /dev/null
+++ b/Lib/test/test_email/test_utils.py
@@ -0,0 +1,45 @@
+import datetime
+from email import utils
+import unittest
+
+class DateTimeTests(unittest.TestCase):
+
+ datestring = 'Sun, 23 Sep 2001 20:10:55'
+ dateargs = (2001, 9, 23, 20, 10, 55)
+ offsetstring = ' -0700'
+ utcoffset = datetime.timedelta(hours=-7)
+ tz = datetime.timezone(utcoffset)
+ naive_dt = datetime.datetime(*dateargs)
+ aware_dt = datetime.datetime(*dateargs, tzinfo=tz)
+
+ def test_naive_datetime(self):
+ self.assertEqual(utils.format_datetime(self.naive_dt),
+ self.datestring + ' -0000')
+
+ def test_aware_datetime(self):
+ self.assertEqual(utils.format_datetime(self.aware_dt),
+ self.datestring + self.offsetstring)
+
+ def test_usegmt(self):
+ utc_dt = datetime.datetime(*self.dateargs,
+ tzinfo=datetime.timezone.utc)
+ self.assertEqual(utils.format_datetime(utc_dt, usegmt=True),
+ self.datestring + ' GMT')
+
+ def test_usegmt_with_naive_datetime_raises(self):
+ with self.assertRaises(ValueError):
+ utils.format_datetime(self.naive_dt, usegmt=True)
+
+ def test_usegmt_with_non_utc_datetime_raises(self):
+ with self.assertRaises(ValueError):
+ utils.format_datetime(self.aware_dt, usegmt=True)
+
+ def test_parsedate_to_datetime(self):
+ self.assertEqual(
+ utils.parsedate_to_datetime(self.datestring + self.offsetstring),
+ self.aware_dt)
+
+ def test_parsedate_to_datetime_naive(self):
+ self.assertEqual(
+ utils.parsedate_to_datetime(self.datestring + ' -0000'),
+ self.naive_dt)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -234,6 +234,9 @@
Library
-------
+- Issue #665194: email.utils now has format_datetime and parsedate_to_datetime
+ functions, allowing for round tripping of RFC2822 format dates.
+
- Issue #12571: Add a plat-linux3 directory mirroring the plat-linux2
directory, so that "import DLFCN" and other similar imports work on
Linux 3.0.
--
Repository URL: http://hg.python.org/cpython
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