Edgewall Software
Modify

Opened 5 years ago

Closed 5 years ago

Last modified 2 years ago

#11563 closed defect (fixed)

Three datefmt.to_datetime() tests fail when TZ=Europe/London

Reported by: Alex Willmerer <al.willmer@…> Owned by: Jun Omae
Priority: normal Milestone: 0.12.6
Component: general Version: 1.1.1dev
Severity: normal Keywords: timezone
Cc:
Release Notes:

Fix LocalTimezone with date/time on DST boundaries and timezone changes different from current standard and daylight timezones.

API Changes:

Description (last modified by Ryan J Ollos)

Three unit tests in source:/trunk/trac/util/tests/datefmt.py fail in latest trunk (r12624 on Ubuntu 13.10/Python 2.7.5, set to the UK timezone. trac.util.to_datetime(<n>) returns a datetime that is 1 hour ahead of that returned by datetime.fromtimestamp(<n>), where n is a POSIX timestamp.

In January 1970 the UK was 1 hour ahead of UTC. This was changed in October 1971, since then the UK has been on GMT (UTC+0) during winter months.

(venv)$ PYTHONPATH=. python trac/util/tests/datefmt.py
................F.FF...................................................................................
======================================================================
FAIL: test_to_datetime (__main__.DateFormatTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "trac/util/tests/datefmt.py", line 716, in test_to_datetime
    self.assertEqual(datefmt.to_datetime(23), expected)
AssertionError: datetime.datetime(1970, 1, 1, 2, 0, 23, tzinfo=<LocalTimezone "GMT" 0:00:00>) != datetime.datetime(1970, 1, 1, 1, 0, 23, tzinfo=<LocalTimezone "GMT" 0:00:00>)

======================================================================
FAIL: test_to_datetime_microsecond_negative_timestamps (__main__.DateFormatTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "trac/util/tests/datefmt.py", line 734, in test_to_datetime_microsecond_negative_timestamps
    self.assertEqual(datefmt.to_datetime(-2345678912), expected)
AssertionError: datetime.datetime(1970, 1, 1, 1, 20, 54, 321088, tzinfo=<LocalTimezone "GMT" 0:00:00>) != datetime.datetime(1970, 1, 1, 0, 20, 54, 321088, tzinfo=<LocalTimezone "GMT" 0:00:00>)

======================================================================
FAIL: test_to_datetime_microsecond_timestamps (__main__.DateFormatTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "trac/util/tests/datefmt.py", line 723, in test_to_datetime_microsecond_timestamps
    self.assertEqual(datefmt.to_datetime(2345678912), expected)
AssertionError: datetime.datetime(1970, 1, 1, 2, 39, 5, 678912, tzinfo=<LocalTimezone "GMT" 0:00:00>) != datetime.datetime(1970, 1, 1, 1, 39, 5, 678912, tzinfo=<LocalTimezone "GMT" 0:00:00>)

----------------------------------------------------------------------
Ran 103 tests in 0.355s

FAILED (failures=3)

Other timezones are not affected (checked by Jun Omae)

$ git status -sb
## 0.12-stable
$ TZ=Europe/London ~/venv/py24/bin/python setup.py test -s trac.util.tests.datefmt.suite ...
FAILED (failures=3)
$ TZ=GMT ~/venv/py24/bin/python setup.py test -s trac.util.tests.datefmt.suite ...
OK
$ TZ=Europe/Berlin ~/venv/py24/bin/python setup.py test -s trac.util.tests.datefmt.suite ...
OK

This was initially discussed in trac-dev:wzKUgAe38PU/hJEP8mwfRc4J.

Attachments (0)

Change History (8)

comment:1 Changed 5 years ago by Jun Omae

Milestone: 0.12.6
Owner: set to Jun Omae
Status: newassigned

Proposed changes in jomae.git@t11563.

This issue occurs when the date/time has timezone which is different from time.timezone and time.altzone.

time std dst
now GMT BST (GMT+0100)
1968 - 1971 BST (GMT+0100) n/a

comment:2 Changed 5 years ago by Jun Omae

Improved unit tests in [500f3a78/jomae.git].

comment:3 Changed 5 years ago by Alex Willmer <al.willmer@…>

All trac.util tests pass for me

(venv)~/src/d4/jomae$ git branch
* t11563
  trunk
(venv)~/src/d4/jomae$ python setup.py test -s trac.util.tests.suite
running test
running egg_info
writing requirements to Trac.egg-info/requires.txt
writing Trac.egg-info/PKG-INFO
writing top-level names to Trac.egg-info/top_level.txt
writing dependency_links to Trac.egg-info/dependency_links.txt
writing entry points to Trac.egg-info/entry_points.txt
reading manifest file 'Trac.egg-info/SOURCES.txt'
writing manifest file 'Trac.egg-info/SOURCES.txt'
running build_ext
test_existing (trac.util.tests.AtomicFileTestCase) ... ok
test_existing_open_for_reading (trac.util.tests.AtomicFileTestCase) ... ok
...
test_tracerror_with_tgettext (trac.util.tests.html.ToFragmentTestCase) ... ok
test_unicode (trac.util.tests.html.ToFragmentTestCase) ... ok

----------------------------------------------------------------------
Ran 169 tests in 0.587s

OK

comment:4 Changed 5 years ago by Jun Omae

I noticed that another issue on DST boundaries and timezone changes, e.g. 2011-03-27 02:00 and 2010-10-31 03:00 in Moscow. It's different between pytz's timezone and localtz in trac.util.datefmt.

>>> import os
>>> from datetime import datetime
>>> from trac.util.datefmt import to_datetime, get_timezone, localtz
>>> os.environ['TZ']
'Europe/Moscow'
>>> localtz
<LocalTimezone "MSK" 4:00:00 "MSK" 4:00:00>
>>> tz = get_timezone('Europe/Moscow')
>>>
>>> t = datetime(2011, 3, 27, 2)
>>> to_datetime(t, tz)
datetime.datetime(2011, 3, 27, 3, 0, tzinfo=<DstTzInfo 'Europe/Moscow' MSK+4:00:00 STD>)
>>> to_datetime(t, localtz)
datetime.datetime(2011, 3, 27, 1, 0, tzinfo=<LocalTimezone "MSK" 4:00:00>)
>>>
>>> t = datetime(2010, 10, 31, 3)
>>> to_datetime(t, tz)
datetime.datetime(2010, 10, 31, 3, 0, tzinfo=<DstTzInfo 'Europe/Moscow' MSK+3:00:00 STD>)
>>> to_datetime(t, localtz)
datetime.datetime(2010, 10, 31, 2, 0, tzinfo=<LocalTimezone "MSK" 4:00:00>)

I updated the branch jomae.git@t11563 and added more unit tests.

>>> t = datetime(2011, 3, 27, 2)
>>> to_datetime(t, tz)
datetime.datetime(2011, 3, 27, 3, 0, tzinfo=<DstTzInfo 'Europe/Moscow' MSK+4:00:00 STD>)
>>> to_datetime(t, localtz)
datetime.datetime(2011, 3, 27, 3, 0, tzinfo=<LocalTimezone "MSK" 4:00:00>)
>>>
>>> t = datetime(2010, 10, 31, 3)
>>> to_datetime(t, tz)
datetime.datetime(2010, 10, 31, 3, 0, tzinfo=<DstTzInfo 'Europe/Moscow' MSK+3:00:00 STD>)
>>> to_datetime(t, localtz)
datetime.datetime(2010, 10, 31, 3, 0, tzinfo=<LocalTimezone "UTC+03:00" 3:00:00>)

In the branch, all unit tests pass with Python 2.4-2.7 on i386 and x86-64.

I'll push it tonight.

comment:5 Changed 5 years ago by Jun Omae

Release Notes: modified (diff)
Resolution: fixed
Status: assignedclosed

Committed in [12633] and merged in [12634-12635].

comment:6 Changed 4 years ago by Ryan J Ollos

Description: modified (diff)

comment:7 Changed 3 years ago by Ryan J Ollos

Proposed refactoring to address confusing line and unpythonic is True:

  • trac/util/datefmt.py

    diff --git a/trac/util/datefmt.py b/trac/util/datefmt.py
    index 659b7f7..4f8bac2 100644
    a b class LocalTimezone(tzinfo):  
    10221022            if not std_correct:
    10231023                raise ValueError('Non existent time "%s"' % dt)
    10241024        tt = None
    1025         if std_correct is dst_correct is True:
     1025        if std_correct and dst_correct:
    10261026            tt = local_tt[bool(is_dst)]
    1027         elif std_correct is True:
     1027        elif std_correct:
    10281028            tt = local_tt[0]
    1029         elif dst_correct is True:
     1029        elif dst_correct:
    10301030            tt = local_tt[1]
    10311031        if tt:
    10321032            utc_ts = to_timestamp(datetime(tzinfo=utc, *tt[:6]))

Unit tests pass for me after the change.

comment:8 Changed 2 years ago by anonymous

comment:7 changes committed in [14732].

Modify Ticket

Change Properties
Set your email in Preferences
Action
as closed The owner will remain Jun Omae.
The resolution will be deleted.
to The owner will be changed from Jun Omae to the specified user.

Add Comment


E-mail address and name can be saved in the Preferences .
 
Note: See TracTickets for help on using tickets.