diff options
| -rw-r--r-- | Doc/library/datetime.rst | 32 | ||||
| -rw-r--r-- | Lib/_pydatetime.py | 35 | ||||
| -rw-r--r-- | Lib/test/datetimetester.py | 64 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2024-01-30-22-10-50.gh-issue-49766.yulJL_.rst | 8 | ||||
| -rw-r--r-- | Modules/_datetimemodule.c | 36 |
5 files changed, 91 insertions, 84 deletions
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst index 930af6c..a46eed3 100644 --- a/Doc/library/datetime.rst +++ b/Doc/library/datetime.rst @@ -619,11 +619,27 @@ Notes: (4) :class:`date` objects are equal if they represent the same date. + :class:`!date` objects that are not also :class:`.datetime` instances + are never equal to :class:`!datetime` objects, even if they represent + the same date. + (5) *date1* is considered less than *date2* when *date1* precedes *date2* in time. In other words, ``date1 < date2`` if and only if ``date1.toordinal() < date2.toordinal()``. + Order comparison between a :class:`!date` object that is not also a + :class:`.datetime` instance and a :class:`!datetime` object raises + :exc:`TypeError`. + +.. versionchanged:: 3.13 + Comparison between :class:`.datetime` object and an instance of + the :class:`date` subclass that is not a :class:`!datetime` subclass + no longer coverts the latter to :class:`!date`, ignoring the time part + and the time zone. + The default behavior can be changed by overriding the special comparison + methods in subclasses. + In Boolean contexts, all :class:`date` objects are considered to be true. Instance methods: @@ -1192,9 +1208,6 @@ Supported operations: and time, taking into account the time zone. Naive and aware :class:`!datetime` objects are never equal. - :class:`!datetime` objects are never equal to :class:`date` objects - that are not also :class:`!datetime` instances, even if they represent - the same date. If both comparands are aware and have different :attr:`~.datetime.tzinfo` attributes, the comparison acts as comparands were first converted to UTC @@ -1206,9 +1219,8 @@ Supported operations: *datetime1* is considered less than *datetime2* when *datetime1* precedes *datetime2* in time, taking into account the time zone. - Order comparison between naive and aware :class:`.datetime` objects, - as well as a :class:`!datetime` object and a :class:`!date` object - that is not also a :class:`!datetime` instance, raises :exc:`TypeError`. + Order comparison between naive and aware :class:`.datetime` objects + raises :exc:`TypeError`. If both comparands are aware and have different :attr:`~.datetime.tzinfo` attributes, the comparison acts as comparands were first converted to UTC @@ -1218,6 +1230,14 @@ Supported operations: Equality comparisons between aware and naive :class:`.datetime` instances don't raise :exc:`TypeError`. +.. versionchanged:: 3.13 + Comparison between :class:`.datetime` object and an instance of + the :class:`date` subclass that is not a :class:`!datetime` subclass + no longer coverts the latter to :class:`!date`, ignoring the time part + and the time zone. + The default behavior can be changed by overriding the special comparison + methods in subclasses. + Instance methods: .. method:: datetime.date() diff --git a/Lib/_pydatetime.py b/Lib/_pydatetime.py index 54c12d3..b7d569c 100644 --- a/Lib/_pydatetime.py +++ b/Lib/_pydatetime.py @@ -556,10 +556,6 @@ def _check_tzinfo_arg(tz): if tz is not None and not isinstance(tz, tzinfo): raise TypeError("tzinfo argument must be None or of a tzinfo subclass") -def _cmperror(x, y): - raise TypeError("can't compare '%s' to '%s'" % ( - type(x).__name__, type(y).__name__)) - def _divide_and_round(a, b): """divide a by b and round result to the nearest integer @@ -1113,32 +1109,33 @@ class date: # Comparisons of date objects with other. def __eq__(self, other): - if isinstance(other, date): + if isinstance(other, date) and not isinstance(other, datetime): return self._cmp(other) == 0 return NotImplemented def __le__(self, other): - if isinstance(other, date): + if isinstance(other, date) and not isinstance(other, datetime): return self._cmp(other) <= 0 return NotImplemented def __lt__(self, other): - if isinstance(other, date): + if isinstance(other, date) and not isinstance(other, datetime): return self._cmp(other) < 0 return NotImplemented def __ge__(self, other): - if isinstance(other, date): + if isinstance(other, date) and not isinstance(other, datetime): return self._cmp(other) >= 0 return NotImplemented def __gt__(self, other): - if isinstance(other, date): + if isinstance(other, date) and not isinstance(other, datetime): return self._cmp(other) > 0 return NotImplemented def _cmp(self, other): assert isinstance(other, date) + assert not isinstance(other, datetime) y, m, d = self._year, self._month, self._day y2, m2, d2 = other._year, other._month, other._day return _cmp((y, m, d), (y2, m2, d2)) @@ -2137,42 +2134,32 @@ class datetime(date): def __eq__(self, other): if isinstance(other, datetime): return self._cmp(other, allow_mixed=True) == 0 - elif not isinstance(other, date): - return NotImplemented else: - return False + return NotImplemented def __le__(self, other): if isinstance(other, datetime): return self._cmp(other) <= 0 - elif not isinstance(other, date): - return NotImplemented else: - _cmperror(self, other) + return NotImplemented def __lt__(self, other): if isinstance(other, datetime): return self._cmp(other) < 0 - elif not isinstance(other, date): - return NotImplemented else: - _cmperror(self, other) + return NotImplemented def __ge__(self, other): if isinstance(other, datetime): return self._cmp(other) >= 0 - elif not isinstance(other, date): - return NotImplemented else: - _cmperror(self, other) + return NotImplemented def __gt__(self, other): if isinstance(other, datetime): return self._cmp(other) > 0 - elif not isinstance(other, date): - return NotImplemented else: - _cmperror(self, other) + return NotImplemented def _cmp(self, other, allow_mixed=False): assert isinstance(other, datetime) diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 53ad5e5..980a8e6 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -5435,42 +5435,50 @@ class TestTimezoneConversions(unittest.TestCase): class Oddballs(unittest.TestCase): - def test_bug_1028306(self): + def test_date_datetime_comparison(self): + # bpo-1028306, bpo-5516 (gh-49766) # Trying to compare a date to a datetime should act like a mixed- # type comparison, despite that datetime is a subclass of date. as_date = date.today() as_datetime = datetime.combine(as_date, time()) - self.assertTrue(as_date != as_datetime) - self.assertTrue(as_datetime != as_date) - self.assertFalse(as_date == as_datetime) - self.assertFalse(as_datetime == as_date) - self.assertRaises(TypeError, lambda: as_date < as_datetime) - self.assertRaises(TypeError, lambda: as_datetime < as_date) - self.assertRaises(TypeError, lambda: as_date <= as_datetime) - self.assertRaises(TypeError, lambda: as_datetime <= as_date) - self.assertRaises(TypeError, lambda: as_date > as_datetime) - self.assertRaises(TypeError, lambda: as_datetime > as_date) - self.assertRaises(TypeError, lambda: as_date >= as_datetime) - self.assertRaises(TypeError, lambda: as_datetime >= as_date) - - # Nevertheless, comparison should work with the base-class (date) - # projection if use of a date method is forced. - self.assertEqual(as_date.__eq__(as_datetime), True) - different_day = (as_date.day + 1) % 20 + 1 - as_different = as_datetime.replace(day= different_day) - self.assertEqual(as_date.__eq__(as_different), False) + date_sc = SubclassDate(as_date.year, as_date.month, as_date.day) + datetime_sc = SubclassDatetime(as_date.year, as_date.month, + as_date.day, 0, 0, 0) + for d in (as_date, date_sc): + for dt in (as_datetime, datetime_sc): + for x, y in (d, dt), (dt, d): + self.assertTrue(x != y) + self.assertFalse(x == y) + self.assertRaises(TypeError, lambda: x < y) + self.assertRaises(TypeError, lambda: x <= y) + self.assertRaises(TypeError, lambda: x > y) + self.assertRaises(TypeError, lambda: x >= y) # And date should compare with other subclasses of date. If a # subclass wants to stop this, it's up to the subclass to do so. - date_sc = SubclassDate(as_date.year, as_date.month, as_date.day) - self.assertEqual(as_date, date_sc) - self.assertEqual(date_sc, as_date) - # Ditto for datetimes. - datetime_sc = SubclassDatetime(as_datetime.year, as_datetime.month, - as_date.day, 0, 0, 0) - self.assertEqual(as_datetime, datetime_sc) - self.assertEqual(datetime_sc, as_datetime) + for x, y in ((as_date, date_sc), + (date_sc, as_date), + (as_datetime, datetime_sc), + (datetime_sc, as_datetime)): + self.assertTrue(x == y) + self.assertFalse(x != y) + self.assertFalse(x < y) + self.assertFalse(x > y) + self.assertTrue(x <= y) + self.assertTrue(x >= y) + + # Nevertheless, comparison should work if other object is an instance + # of date or datetime class with overridden comparison operators. + # So special methods should return NotImplemented, as if + # date and datetime were independent classes. + for x, y in (as_date, as_datetime), (as_datetime, as_date): + self.assertEqual(x.__eq__(y), NotImplemented) + self.assertEqual(x.__ne__(y), NotImplemented) + self.assertEqual(x.__lt__(y), NotImplemented) + self.assertEqual(x.__gt__(y), NotImplemented) + self.assertEqual(x.__gt__(y), NotImplemented) + self.assertEqual(x.__ge__(y), NotImplemented) def test_extra_attributes(self): with self.assertWarns(DeprecationWarning): diff --git a/Misc/NEWS.d/next/Library/2024-01-30-22-10-50.gh-issue-49766.yulJL_.rst b/Misc/NEWS.d/next/Library/2024-01-30-22-10-50.gh-issue-49766.yulJL_.rst new file mode 100644 index 0000000..eaaa3ba --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-01-30-22-10-50.gh-issue-49766.yulJL_.rst @@ -0,0 +1,8 @@ +Fix :class:`~datetime.date`-:class:`~datetime.datetime` comparison. Now the +special comparison methods like ``__eq__`` and ``__lt__`` return +:data:`NotImplemented` if one of comparands is :class:`!date` and other is +:class:`!datetime` instead of ignoring the time part and the time zone or +forcefully return "not equal" or raise :exc:`TypeError`. It makes comparison +of :class:`!date` and :class:`!datetime` subclasses more symmetric and +allows to change the default behavior by overriding the special comparison +methods in subclasses. diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index 9b8e0a7..b984ea6 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -1816,16 +1816,6 @@ diff_to_bool(int diff, int op) Py_RETURN_RICHCOMPARE(diff, 0, op); } -/* Raises a "can't compare" TypeError and returns NULL. */ -static PyObject * -cmperror(PyObject *a, PyObject *b) -{ - PyErr_Format(PyExc_TypeError, - "can't compare %s to %s", - Py_TYPE(a)->tp_name, Py_TYPE(b)->tp_name); - return NULL; -} - /* --------------------------------------------------------------------------- * Class implementations. */ @@ -3448,7 +3438,15 @@ date_isocalendar(PyDateTime_Date *self, PyObject *Py_UNUSED(ignored)) static PyObject * date_richcompare(PyObject *self, PyObject *other, int op) { - if (PyDate_Check(other)) { + /* Since DateTime is a subclass of Date, if the other object is + * a DateTime, it would compute an equality testing or an ordering + * based on the date part alone, and we don't want that. + * So return NotImplemented here in that case. + * If a subclass wants to change this, it's up to the subclass to do so. + * The behavior is the same as if Date and DateTime were independent + * classes. + */ + if (PyDate_Check(other) && !PyDateTime_Check(other)) { int diff = memcmp(((PyDateTime_Date *)self)->data, ((PyDateTime_Date *)other)->data, _PyDateTime_DATE_DATASIZE); @@ -5880,21 +5878,7 @@ datetime_richcompare(PyObject *self, PyObject *other, int op) PyObject *offset1, *offset2; int diff; - if (! PyDateTime_Check(other)) { - if (PyDate_Check(other)) { - /* Prevent invocation of date_richcompare. We want to - return NotImplemented here to give the other object - a chance. But since DateTime is a subclass of - Date, if the other object is a Date, it would - compute an ordering based on the date part alone, - and we don't want that. So force unequal or - uncomparable here in that case. */ - if (op == Py_EQ) - Py_RETURN_FALSE; - if (op == Py_NE) - Py_RETURN_TRUE; - return cmperror(self, other); - } + if (!PyDateTime_Check(other)) { Py_RETURN_NOTIMPLEMENTED; } |