From 5e6661bce968173fa45b74fa2111098645ff609c Mon Sep 17 00:00:00 2001 From: Alan Williams Date: Sun, 19 Mar 2023 19:20:20 -0500 Subject: [PATCH] gh-72346: Added isdst deprecation warning to email.utils.localtime (GH-91450) --- Doc/library/email.utils.rst | 20 +++++----- Doc/whatsnew/3.12.rst | 3 ++ Lib/email/utils.py | 40 +++++-------------- Lib/test/test_email/test_utils.py | 13 ++++-- ...2-04-11-18-34-33.gh-issue-72346.pC7gnM.rst | 1 + 5 files changed, 33 insertions(+), 44 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2022-04-11-18-34-33.gh-issue-72346.pC7gnM.rst diff --git a/Doc/library/email.utils.rst b/Doc/library/email.utils.rst index 0e266b6a457..345b64001c1 100644 --- a/Doc/library/email.utils.rst +++ b/Doc/library/email.utils.rst @@ -13,19 +13,17 @@ module: .. function:: localtime(dt=None) - Return local time as an aware datetime object. If called without - arguments, return current time. Otherwise *dt* argument should be a - :class:`~datetime.datetime` instance, and it is converted to the local time - zone according to the system time zone database. If *dt* is naive (that - is, ``dt.tzinfo`` is ``None``), it is assumed to be in local time. In this - case, a positive or zero value for *isdst* causes ``localtime`` to presume - initially that summer time (for example, Daylight Saving Time) is or is not - (respectively) in effect for the specified time. A negative value for - *isdst* causes the ``localtime`` to attempt to divine whether summer time - is in effect for the specified time. + Return local time as an aware datetime object. If called without + arguments, return current time. Otherwise *dt* argument should be a + :class:`~datetime.datetime` instance, and it is converted to the local time + zone according to the system time zone database. If *dt* is naive (that + is, ``dt.tzinfo`` is ``None``), it is assumed to be in local time. The + *isdst* parameter is ignored. - .. versionadded:: 3.3 + .. versionadded:: 3.3 + .. deprecated-removed:: 3.12 3.14 + The *isdst* parameter. .. function:: make_msgid(idstring=None, domain=None) diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst index a36e68528c4..cdd26cd19e7 100644 --- a/Doc/whatsnew/3.12.rst +++ b/Doc/whatsnew/3.12.rst @@ -565,6 +565,9 @@ Pending Removal in Python 3.14 * Creating :c:data:`immutable types ` with mutable bases using the C API. +* Deprecated the *isdst* parameter in :func:`email.utils.localtime`. + (Contributed by Alan Williams in :gh:`72346`.) + * ``__package__`` and ``__cached__`` will cease to be set or taken into consideration by the import system (:gh:`97879`). diff --git a/Lib/email/utils.py b/Lib/email/utils.py index cfdfeb3f1a8..4d014bacd61 100644 --- a/Lib/email/utils.py +++ b/Lib/email/utils.py @@ -331,41 +331,23 @@ def collapse_rfc2231_value(value, errors='replace', # better than not having it. # -def localtime(dt=None, isdst=-1): +def localtime(dt=None, isdst=None): """Return local time as an aware datetime object. If called without arguments, return current time. Otherwise *dt* argument should be a datetime instance, and it is converted to the local time zone according to the system time zone database. If *dt* is naive (that is, dt.tzinfo is None), it is assumed to be in local time. - In this case, a positive or zero value for *isdst* causes localtime to - presume initially that summer time (for example, Daylight Saving Time) - is or is not (respectively) in effect for the specified time. A - negative value for *isdst* causes the localtime() function to attempt - to divine whether summer time is in effect for the specified time. + The isdst parameter is ignored. """ + if isdst is not None: + import warnings + warnings._deprecated( + "The 'isdst' parameter to 'localtime'", + message='{name} is deprecated and slated for removal in Python {remove}', + remove=(3, 14), + ) if dt is None: - return datetime.datetime.now(datetime.timezone.utc).astimezone() - if dt.tzinfo is not None: - return dt.astimezone() - # We have a naive datetime. Convert to a (localtime) timetuple and pass to - # system mktime together with the isdst hint. System mktime will return - # seconds since epoch. - tm = dt.timetuple()[:-1] + (isdst,) - seconds = time.mktime(tm) - localtm = time.localtime(seconds) - try: - delta = datetime.timedelta(seconds=localtm.tm_gmtoff) - tz = datetime.timezone(delta, localtm.tm_zone) - except AttributeError: - # Compute UTC offset and compare with the value implied by tm_isdst. - # If the values match, use the zone name implied by tm_isdst. - delta = dt - datetime.datetime(*time.gmtime(seconds)[:6]) - dst = time.daylight and localtm.tm_isdst > 0 - gmtoff = -(time.altzone if dst else time.timezone) - if delta == datetime.timedelta(seconds=gmtoff): - tz = datetime.timezone(delta, time.tzname[dst]) - else: - tz = datetime.timezone(delta) - return dt.replace(tzinfo=tz) + dt = datetime.datetime.now() + return dt.astimezone() diff --git a/Lib/test/test_email/test_utils.py b/Lib/test/test_email/test_utils.py index 78afb358035..25fa48c5ee2 100644 --- a/Lib/test/test_email/test_utils.py +++ b/Lib/test/test_email/test_utils.py @@ -83,14 +83,14 @@ class LocaltimeTests(unittest.TestCase): def test_localtime_daylight_true_dst_false(self): test.support.patch(self, time, 'daylight', True) t0 = datetime.datetime(2012, 3, 12, 1, 1) - t1 = utils.localtime(t0, isdst=-1) + t1 = utils.localtime(t0) t2 = utils.localtime(t1) self.assertEqual(t1, t2) def test_localtime_daylight_false_dst_false(self): test.support.patch(self, time, 'daylight', False) t0 = datetime.datetime(2012, 3, 12, 1, 1) - t1 = utils.localtime(t0, isdst=-1) + t1 = utils.localtime(t0) t2 = utils.localtime(t1) self.assertEqual(t1, t2) @@ -98,7 +98,7 @@ class LocaltimeTests(unittest.TestCase): def test_localtime_daylight_true_dst_true(self): test.support.patch(self, time, 'daylight', True) t0 = datetime.datetime(2012, 3, 12, 1, 1) - t1 = utils.localtime(t0, isdst=1) + t1 = utils.localtime(t0) t2 = utils.localtime(t1) self.assertEqual(t1, t2) @@ -106,7 +106,7 @@ class LocaltimeTests(unittest.TestCase): def test_localtime_daylight_false_dst_true(self): test.support.patch(self, time, 'daylight', False) t0 = datetime.datetime(2012, 3, 12, 1, 1) - t1 = utils.localtime(t0, isdst=1) + t1 = utils.localtime(t0) t2 = utils.localtime(t1) self.assertEqual(t1, t2) @@ -157,6 +157,11 @@ class LocaltimeTests(unittest.TestCase): t1 = utils.localtime(t0) self.assertEqual(t1.tzname(), 'EET') + def test_isdst_deprecation(self): + with self.assertWarns(DeprecationWarning): + t0 = datetime.datetime(1990, 1, 1) + t1 = utils.localtime(t0, isdst=True) + # Issue #24836: The timezone files are out of date (pre 2011k) # on Mac OS X Snow Leopard. @test.support.requires_mac_ver(10, 7) diff --git a/Misc/NEWS.d/next/Library/2022-04-11-18-34-33.gh-issue-72346.pC7gnM.rst b/Misc/NEWS.d/next/Library/2022-04-11-18-34-33.gh-issue-72346.pC7gnM.rst new file mode 100644 index 00000000000..149ddd706c3 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-04-11-18-34-33.gh-issue-72346.pC7gnM.rst @@ -0,0 +1 @@ +Added deprecation warning to *isdst* parameter of :func:`email.utils.localtime`.