[Python-checkins] r87829 - in python/branches/py3k: Doc/library/time.rst Lib/test/test_time.py Misc/NEWS Modules/timemodule.c
alexander.belopolsky
python-checkins at python.org
Fri Jan 7 20:59:19 CET 2011
Author: alexander.belopolsky
Date: Fri Jan 7 20:59:19 2011
New Revision: 87829
Log:
Issue #10827: Changed the rules for 2-digit years. The time.asctime
function will now format any year when time.accept2dyear is false and
will accept years >= 1000 otherwise. The year range accepted by
time.mktime and time.strftime is still system dependent, but
time.mktime will now accept full range supported by the OS. Conversion
of 2-digit years to 4-digit is deprecated.
Modified:
python/branches/py3k/Doc/library/time.rst
python/branches/py3k/Lib/test/test_time.py
python/branches/py3k/Misc/NEWS
python/branches/py3k/Modules/timemodule.c
Modified: python/branches/py3k/Doc/library/time.rst
==============================================================================
--- python/branches/py3k/Doc/library/time.rst (original)
+++ python/branches/py3k/Doc/library/time.rst Fri Jan 7 20:59:19 2011
@@ -24,9 +24,9 @@
.. index:: single: Year 2038
-* The functions in this module do not handle dates and times before the epoch or
+* The functions in this module may not handle dates and times before the epoch or
far in the future. The cut-off point in the future is determined by the C
- library; for Unix, it is typically in 2038.
+ library; for 32-bit systems, it is typically in 2038.
.. index::
single: Year 2000
@@ -34,20 +34,31 @@
.. _time-y2kissues:
-* **Year 2000 (Y2K) issues**: Python depends on the platform's C library, which
+* **Year 2000 (Y2K) issues**: Python depends on the platform's C library, which
generally doesn't have year 2000 issues, since all dates and times are
- represented internally as seconds since the epoch. Functions accepting a
- :class:`struct_time` (see below) generally require a 4-digit year. For backward
- compatibility, 2-digit years are supported if the module variable
- ``accept2dyear`` is a non-zero integer; this variable is initialized to ``1``
- unless the environment variable :envvar:`PYTHONY2K` is set to a non-empty
- string, in which case it is initialized to ``0``. Thus, you can set
- :envvar:`PYTHONY2K` to a non-empty string in the environment to require 4-digit
- years for all year input. When 2-digit years are accepted, they are converted
- according to the POSIX or X/Open standard: values 69-99 are mapped to 1969-1999,
- and values 0--68 are mapped to 2000--2068. Values 100--1899 are always illegal.
- Note that this is new as of Python 1.5.2(a2); earlier versions, up to Python
- 1.5.1 and 1.5.2a1, would add 1900 to year values below 1900.
+ represented internally as seconds since the epoch. Function :func:`strptime`
+ can parse 2-digit years when given ``%y`` format code. When 2-digit years are
+ parsed, they are converted according to the POSIX and ISO C standards: values
+ 69--99 are mapped to 1969--1999, and values 0--68 are mapped to 2000--2068.
+
+ For backward compatibility, years with less than 4 digits are treated
+ specially by :func:`asctime`, :func:`mktime`, and :func:`strftime` functions
+ that operate on a 9-tuple or :class:`struct_time` values. If year (the first
+ value in the 9-tuple) is specified with less than 4 digits, its interpretation
+ depends on the value of ``accept2dyear`` variable.
+
+ If ``accept2dyear`` is true (default), a backward compatibility behavior is
+ invoked as follows:
+
+ - for 2-digit year, century is guessed according to POSIX rules for
+ ``%y`` strptime format. A deprecation warning is issued when century
+ information is guessed in this way.
+
+ - for 3-digit or negative year, a :exc:`ValueError` exception is raised.
+
+ If ``accept2dyear`` is false (set by the program or as a result of a
+ non-empty value assigned to ``PYTHONY2K`` environment variable) all year
+ values are interpreted as given.
.. index::
single: UTC
Modified: python/branches/py3k/Lib/test/test_time.py
==============================================================================
--- python/branches/py3k/Lib/test/test_time.py (original)
+++ python/branches/py3k/Lib/test/test_time.py Fri Jan 7 20:59:19 2011
@@ -3,6 +3,7 @@
import unittest
import locale
import sysconfig
+import warnings
class TimeTestCase(unittest.TestCase):
@@ -19,10 +20,10 @@
time.clock()
def test_conversions(self):
- self.assertTrue(time.ctime(self.t)
- == time.asctime(time.localtime(self.t)))
- self.assertTrue(int(time.mktime(time.localtime(self.t)))
- == int(self.t))
+ self.assertEqual(time.ctime(self.t),
+ time.asctime(time.localtime(self.t)))
+ self.assertEqual(int(time.mktime(time.localtime(self.t))),
+ int(self.t))
def test_sleep(self):
time.sleep(1.2)
@@ -44,7 +45,7 @@
# Check year [1900, max(int)]
self.assertRaises(ValueError, func,
- (1899, 1, 1, 0, 0, 0, 0, 1, -1))
+ (999, 1, 1, 0, 0, 0, 0, 1, -1))
if time.accept2dyear:
self.assertRaises(ValueError, func,
(-1, 1, 1, 0, 0, 0, 0, 1, -1))
@@ -97,7 +98,8 @@
# No test for daylight savings since strftime() does not change output
# based on its value.
expected = "2000 01 01 00 00 00 1 001"
- result = time.strftime("%Y %m %d %H %M %S %w %j", (0,)*9)
+ with support.check_warnings():
+ result = time.strftime("%Y %m %d %H %M %S %w %j", (0,)*9)
self.assertEqual(expected, result)
def test_strptime(self):
@@ -141,14 +143,15 @@
self.assertEqual(time.ctime(t), 'Sun Sep 16 01:03:52 1973')
t = time.mktime((2000, 1, 1, 0, 0, 0, 0, 0, -1))
self.assertEqual(time.ctime(t), 'Sat Jan 1 00:00:00 2000')
- try:
- bigval = time.mktime((10000, 1, 10) + (0,)*6)
- except (ValueError, OverflowError):
- # If mktime fails, ctime will fail too. This may happen
- # on some platforms.
- pass
- else:
- self.assertEqual(time.ctime(bigval)[-5:], '10000')
+ for year in [-100, 100, 1000, 2000, 10000]:
+ try:
+ testval = time.mktime((year, 1, 10) + (0,)*6)
+ except (ValueError, OverflowError):
+ # If mktime fails, ctime will fail too. This may happen
+ # on some platforms.
+ pass
+ else:
+ self.assertEqual(time.ctime(testval)[20:], str(year))
@unittest.skipIf(not hasattr(time, "tzset"),
"time module has no attribute tzset")
@@ -239,14 +242,14 @@
gt1 = time.gmtime(None)
t0 = time.mktime(gt0)
t1 = time.mktime(gt1)
- self.assertTrue(0 <= (t1-t0) < 0.2)
+ self.assertAlmostEqual(t1, t0, delta=0.2)
def test_localtime_without_arg(self):
lt0 = time.localtime()
lt1 = time.localtime(None)
t0 = time.mktime(lt0)
t1 = time.mktime(lt1)
- self.assertTrue(0 <= (t1-t0) < 0.2)
+ self.assertAlmostEqual(t1, t0, delta=0.2)
class TestLocale(unittest.TestCase):
def setUp(self):
@@ -274,16 +277,18 @@
time.accept2dyear = self.saved_accept2dyear
def yearstr(self, y):
- return time.strftime('%Y', (y,) + (0,) * 8)
+ # return time.strftime('%Y', (y,) + (0,) * 8)
+ return time.asctime((y,) + (0,) * 8).split()[-1]
def test_2dyear(self):
- self.assertEqual(self.yearstr(0), '2000')
- self.assertEqual(self.yearstr(69), '1969')
- self.assertEqual(self.yearstr(68), '2068')
- self.assertEqual(self.yearstr(99), '1999')
+ with support.check_warnings():
+ self.assertEqual(self.yearstr(0), '2000')
+ self.assertEqual(self.yearstr(69), '1969')
+ self.assertEqual(self.yearstr(68), '2068')
+ self.assertEqual(self.yearstr(99), '1999')
def test_invalid(self):
- self.assertRaises(ValueError, self.yearstr, 1899)
+ self.assertRaises(ValueError, self.yearstr, 999)
self.assertRaises(ValueError, self.yearstr, 100)
self.assertRaises(ValueError, self.yearstr, -1)
@@ -293,10 +298,15 @@
class TestDontAccept2Year(TestAccept2Year):
accept2dyear = 0
def test_2dyear(self):
- self.assertRaises(ValueError, self.yearstr, 0)
- self.assertRaises(ValueError, self.yearstr, 69)
- self.assertRaises(ValueError, self.yearstr, 68)
- self.assertRaises(ValueError, self.yearstr, 99)
+ self.assertEqual(self.yearstr(0), '0')
+ self.assertEqual(self.yearstr(69), '69')
+ self.assertEqual(self.yearstr(68), '68')
+ self.assertEqual(self.yearstr(99), '99')
+ self.assertEqual(self.yearstr(999), '999')
+ self.assertEqual(self.yearstr(9999), '9999')
+
+ def test_invalid(self):
+ pass
class TestDontAccept2YearBool(TestDontAccept2Year):
accept2dyear = False
Modified: python/branches/py3k/Misc/NEWS
==============================================================================
--- python/branches/py3k/Misc/NEWS (original)
+++ python/branches/py3k/Misc/NEWS Fri Jan 7 20:59:19 2011
@@ -36,6 +36,14 @@
Library
-------
+- Issue #10827: Changed the rules for 2-digit years. The time.asctime
+ function will now format any year when ``time.accept2dyear`` is
+ false and will accept years >= 1000 otherwise. The year range
+ accepted by ``time.mktime`` and ``time.strftime`` is still system
+ dependent, but ``time.mktime`` will now accept full range supported
+ by the OS. Conversion of 2-digit years to 4-digit is deprecated.
+
+
- Issue #7858: Raise an error properly when os.utime() fails under Windows
on an existing file.
Modified: python/branches/py3k/Modules/timemodule.c
==============================================================================
--- python/branches/py3k/Modules/timemodule.c (original)
+++ python/branches/py3k/Modules/timemodule.c Fri Jan 7 20:59:19 2011
@@ -312,34 +312,42 @@
&p->tm_wday, &p->tm_yday, &p->tm_isdst))
return 0;
- /* XXX: Why 1900? If the goal is to interpret 2-digit years as those in
- * 20th / 21st century according to the POSIX standard, we can just treat
- * 0 <= y < 100 as special. Year 100 is probably too ambiguous and should
- * be rejected, but years 101 through 1899 can be passed through.
+ /* If year is specified with less than 4 digits, its interpretation
+ * depends on the accept2dyear value.
+ *
+ * If accept2dyear is true (default), a backward compatibility behavior is
+ * invoked as follows:
+ *
+ * - for 2-digit year, century is guessed according to POSIX rules for
+ * %y strptime format: 21st century for y < 69, 20th century
+ * otherwise. A deprecation warning is issued when century
+ * information is guessed in this way.
+ *
+ * - for 3-digit or negative year, a ValueError exception is raised.
+ *
+ * If accept2dyear is false (set by the program or as a result of a
+ * non-empty value assigned to PYTHONY2K environment variable) all year
+ * values are interpreted as given.
*/
- if (y < 1900) {
+ if (y < 1000) {
PyObject *accept = PyDict_GetItemString(moddict,
"accept2dyear");
int acceptval = accept != NULL && PyObject_IsTrue(accept);
if (acceptval == -1)
return 0;
if (acceptval) {
- if (69 <= y && y <= 99)
- y += 1900;
- else if (0 <= y && y <= 68)
+ if (0 <= y && y < 69)
y += 2000;
+ else if (69 <= y && y < 100)
+ y += 1900;
else {
PyErr_SetString(PyExc_ValueError,
"year out of range");
return 0;
}
- }
- /* XXX: When accept2dyear is false, we don't have to reject y < 1900.
- * Consider removing the following else-clause. */
- else {
- PyErr_SetString(PyExc_ValueError,
- "year out of range");
- return 0;
+ if (PyErr_WarnEx(PyExc_DeprecationWarning,
+ "Century info guessed for a 2-digit year.", 1) != 0)
+ return 0;
}
}
p->tm_year = y - 1900;
@@ -462,6 +470,15 @@
else if (!gettmarg(tup, &buf) || !checktm(&buf))
return NULL;
+ /* XXX: Reportedly, some systems have issues formating dates prior to year
+ * 1900. These systems should be identified and this check should be
+ * moved to appropriate system specific section below. */
+ if (buf.tm_year < 0) {
+ PyErr_Format(PyExc_ValueError, "year=%d is before 1900; "
+ "the strftime() method requires year >= 1900",
+ buf.tm_year + 1900);
+ }
+
/* Normalize tm_isdst just in case someone foolishly implements %Z
based on the assumption that tm_isdst falls within the range of
[-1, 1] */
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