[Python-3000-checkins] r51561 - in python/branches/p3yk: Lib/test/test_datetime.py Modules/datetimemodule.c
guido.van.rossum
python-3000-checkins at python.org
Thu Aug 24 19:29:40 CEST 2006
Author: guido.van.rossum
Date: Thu Aug 24 19:29:38 2006
New Revision: 51561
Modified:
python/branches/p3yk/Lib/test/test_datetime.py
python/branches/p3yk/Modules/datetimemodule.c
Log:
Fix the datetime comparison conundrum.
The special-casing of other objects with a timetuple attribute is gone.
Let's hope Tim agrees.
Modified: python/branches/p3yk/Lib/test/test_datetime.py
==============================================================================
--- python/branches/p3yk/Lib/test/test_datetime.py (original)
+++ python/branches/p3yk/Lib/test/test_datetime.py Thu Aug 24 19:29:38 2006
@@ -954,41 +954,60 @@
def test_mixed_compare(self):
our = self.theclass(2000, 4, 5)
+
+ # Our class can be compared for equality to other classes
+ self.assertEqual(our == 1, False)
+ self.assertEqual(1 == our, False)
+ self.assertEqual(our != 1, True)
+ self.assertEqual(1 != our, True)
+
+ # But the ordering is undefined
+ self.assertRaises(TypeError, lambda: our < 1)
+ self.assertRaises(TypeError, lambda: 1 < our)
self.assertRaises(TypeError, cmp, our, 1)
self.assertRaises(TypeError, cmp, 1, our)
- class AnotherDateTimeClass(object):
- def __cmp__(self, other):
- # Return "equal" so calling this can't be confused with
- # compare-by-address (which never says "equal" for distinct
- # objects).
- return 0
-
- # This still errors, because date and datetime comparison raise
- # TypeError instead of NotImplemented when they don't know what to
- # do, in order to stop comparison from falling back to the default
- # compare-by-address.
- their = AnotherDateTimeClass()
+ # Repeat those tests with a different class
+
+ class SomeClass:
+ pass
+
+ their = SomeClass()
+ self.assertEqual(our == their, False)
+ self.assertEqual(their == our, False)
+ self.assertEqual(our != their, True)
+ self.assertEqual(their != our, True)
+ self.assertRaises(TypeError, lambda: our < their)
+ self.assertRaises(TypeError, lambda: their < our)
self.assertRaises(TypeError, cmp, our, their)
- # Oops: The next stab raises TypeError in the C implementation,
- # but not in the Python implementation of datetime. The difference
- # is due to that the Python implementation defines __cmp__ but
- # the C implementation defines tp_richcompare. This is more pain
- # to fix than it's worth, so commenting out the test.
- # self.assertEqual(cmp(their, our), 0)
-
- # But date and datetime comparison return NotImplemented instead if the
- # other object has a timetuple attr. This gives the other object a
- # chance to do the comparison.
- class Comparable(AnotherDateTimeClass):
- def timetuple(self):
- return ()
-
- their = Comparable()
- self.assertEqual(cmp(our, their), 0)
- self.assertEqual(cmp(their, our), 0)
- self.failUnless(our == their)
- self.failUnless(their == our)
+ self.assertRaises(TypeError, cmp, their, our)
+
+ # However, if the other class explicitly defines ordering
+ # relative to our class, it is allowed to do so
+
+ class LargerThanAnything:
+ def __lt__(self, other):
+ return False
+ def __le__(self, other):
+ return isinstance(other, LargerThanAnything)
+ def __eq__(self, other):
+ return isinstance(other, LargerThanAnything)
+ def __ne__(self, other):
+ return not isinstance(other, LargerThanAnything)
+ def __gt__(self, other):
+ return not isinstance(other, LargerThanAnything)
+ def __ge__(self, other):
+ return True
+
+ their = LargerThanAnything()
+ self.assertEqual(our == their, False)
+ self.assertEqual(their == our, False)
+ self.assertEqual(our != their, True)
+ self.assertEqual(their != our, True)
+ self.assertEqual(our < their, True)
+ self.assertEqual(their < our, False)
+ self.assertEqual(cmp(our, their), -1)
+ self.assertEqual(cmp(their, our), 1)
def test_bool(self):
# All dates are considered true.
@@ -3217,10 +3236,10 @@
# Neverthelss, comparison should work with the base-class (date)
# projection if use of a date method is forced.
- self.assert_(as_date.__eq__(as_datetime))
+ self.assertEqual(as_date.__eq__(as_datetime), True)
different_day = (as_date.day + 1) % 20 + 1
- self.assert_(not as_date.__eq__(as_datetime.replace(day=
- different_day)))
+ as_different = as_datetime.replace(day= different_day)
+ self.assertEqual(as_date.__eq__(as_different), False)
# 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.
Modified: python/branches/p3yk/Modules/datetimemodule.c
==============================================================================
--- python/branches/p3yk/Modules/datetimemodule.c (original)
+++ python/branches/p3yk/Modules/datetimemodule.c Thu Aug 24 19:29:38 2006
@@ -1387,7 +1387,7 @@
* Miscellaneous helpers.
*/
-/* For obscure reasons, we need to use tp_richcompare instead of tp_compare.
+/* For various reasons, we need to use tp_richcompare instead of tp_compare.
* The comparisons here all most naturally compute a cmp()-like result.
* This little helper turns that into a bool result for rich comparisons.
*/
@@ -1705,31 +1705,23 @@
return result;
}
-/* This is more natural as a tp_compare, but doesn't work then: for whatever
- * reason, Python's try_3way_compare ignores tp_compare unless
- * PyInstance_Check returns true, but these aren't old-style classes.
- */
static PyObject *
-delta_richcompare(PyDateTime_Delta *self, PyObject *other, int op)
+delta_richcompare(PyObject *self, PyObject *other, int op)
{
- int diff = 42; /* nonsense */
-
if (PyDelta_Check(other)) {
- diff = GET_TD_DAYS(self) - GET_TD_DAYS(other);
+ int diff = GET_TD_DAYS(self) - GET_TD_DAYS(other);
if (diff == 0) {
diff = GET_TD_SECONDS(self) - GET_TD_SECONDS(other);
if (diff == 0)
diff = GET_TD_MICROSECONDS(self) -
GET_TD_MICROSECONDS(other);
}
+ return diff_to_bool(diff, op);
+ }
+ else {
+ Py_INCREF(Py_NotImplemented);
+ return Py_NotImplemented;
}
- else if (op == Py_EQ || op == Py_NE)
- diff = 1; /* any non-zero value will do */
-
- else /* stop this from falling back to address comparison */
- return cmperror((PyObject *)self, other);
-
- return diff_to_bool(diff, op);
}
static PyObject *delta_getstate(PyDateTime_Delta *self);
@@ -2145,7 +2137,7 @@
delta_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
- (richcmpfunc)delta_richcompare, /* tp_richcompare */
+ delta_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
@@ -2499,31 +2491,19 @@
/* Miscellaneous methods. */
-/* This is more natural as a tp_compare, but doesn't work then: for whatever
- * reason, Python's try_3way_compare ignores tp_compare unless
- * PyInstance_Check returns true, but these aren't old-style classes.
- */
static PyObject *
-date_richcompare(PyDateTime_Date *self, PyObject *other, int op)
+date_richcompare(PyObject *self, PyObject *other, int op)
{
- int diff = 42; /* nonsense */
-
- if (PyDate_Check(other))
- diff = memcmp(self->data, ((PyDateTime_Date *)other)->data,
- _PyDateTime_DATE_DATASIZE);
-
- else if (PyObject_HasAttrString(other, "timetuple")) {
- /* A hook for other kinds of date objects. */
+ if (PyDate_Check(other)) {
+ int diff = memcmp(((PyDateTime_Date *)self)->data,
+ ((PyDateTime_Date *)other)->data,
+ _PyDateTime_DATE_DATASIZE);
+ return diff_to_bool(diff, op);
+ }
+ else {
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
- else if (op == Py_EQ || op == Py_NE)
- diff = 1; /* any non-zero value will do */
-
- else /* stop this from falling back to address comparison */
- return cmperror((PyObject *)self, other);
-
- return diff_to_bool(diff, op);
}
static PyObject *
@@ -2701,7 +2681,7 @@
date_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
- (richcmpfunc)date_richcompare, /* tp_richcompare */
+ date_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
@@ -3223,28 +3203,19 @@
* Miscellaneous methods.
*/
-/* This is more natural as a tp_compare, but doesn't work then: for whatever
- * reason, Python's try_3way_compare ignores tp_compare unless
- * PyInstance_Check returns true, but these aren't old-style classes.
- */
static PyObject *
-time_richcompare(PyDateTime_Time *self, PyObject *other, int op)
+time_richcompare(PyObject *self, PyObject *other, int op)
{
int diff;
naivety n1, n2;
int offset1, offset2;
if (! PyTime_Check(other)) {
- if (op == Py_EQ || op == Py_NE) {
- PyObject *result = op == Py_EQ ? Py_False : Py_True;
- Py_INCREF(result);
- return result;
- }
- /* Stop this from falling back to address comparison. */
- return cmperror((PyObject *)self, other);
+ Py_INCREF(Py_NotImplemented);
+ return Py_NotImplemented;
}
- if (classify_two_utcoffsets((PyObject *)self, &offset1, &n1, Py_None,
- other, &offset2, &n2, Py_None) < 0)
+ if (classify_two_utcoffsets(self, &offset1, &n1, Py_None,
+ other, &offset2, &n2, Py_None) < 0)
return NULL;
assert(n1 != OFFSET_UNKNOWN && n2 != OFFSET_UNKNOWN);
/* If they're both naive, or both aware and have the same offsets,
@@ -3252,7 +3223,8 @@
* offset2 == 0 at this point.
*/
if (n1 == n2 && offset1 == offset2) {
- diff = memcmp(self->data, ((PyDateTime_Time *)other)->data,
+ diff = memcmp(((PyDateTime_Time *)self)->data,
+ ((PyDateTime_Time *)other)->data,
_PyDateTime_TIME_DATASIZE);
return diff_to_bool(diff, op);
}
@@ -3474,7 +3446,7 @@
time_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
- (richcmpfunc)time_richcompare, /* tp_richcompare */
+ time_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
@@ -4115,46 +4087,34 @@
/* Miscellaneous methods. */
-/* This is more natural as a tp_compare, but doesn't work then: for whatever
- * reason, Python's try_3way_compare ignores tp_compare unless
- * PyInstance_Check returns true, but these aren't old-style classes.
- */
static PyObject *
-datetime_richcompare(PyDateTime_DateTime *self, PyObject *other, int op)
+datetime_richcompare(PyObject *self, PyObject *other, int op)
{
int diff;
naivety n1, n2;
int offset1, offset2;
if (! PyDateTime_Check(other)) {
- /* If other has a "timetuple" attr, that's an advertised
- * hook for other classes to ask to get comparison control.
- * However, date instances have a timetuple attr, and we
- * don't want to allow that comparison. Because datetime
- * is a subclass of date, when mixing date and datetime
- * in a comparison, Python gives datetime the first shot
- * (it's the more specific subtype). So we can stop that
- * combination here reliably.
- */
- if (PyObject_HasAttrString(other, "timetuple") &&
- ! PyDate_Check(other)) {
- /* A hook for other kinds of datetime objects. */
- Py_INCREF(Py_NotImplemented);
- return Py_NotImplemented;
- }
- if (op == Py_EQ || op == Py_NE) {
- PyObject *result = op == Py_EQ ? Py_False : Py_True;
- Py_INCREF(result);
- return result;
- }
- /* Stop this from falling back to address comparison. */
- return cmperror((PyObject *)self, other);
- }
-
- if (classify_two_utcoffsets((PyObject *)self, &offset1, &n1,
- (PyObject *)self,
- other, &offset2, &n2,
- other) < 0)
+ 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);
+ }
+ Py_INCREF(Py_NotImplemented);
+ return Py_NotImplemented;
+ }
+
+ if (classify_two_utcoffsets(self, &offset1, &n1, self,
+ other, &offset2, &n2, other) < 0)
return NULL;
assert(n1 != OFFSET_UNKNOWN && n2 != OFFSET_UNKNOWN);
/* If they're both naive, or both aware and have the same offsets,
@@ -4162,7 +4122,8 @@
* offset2 == 0 at this point.
*/
if (n1 == n2 && offset1 == offset2) {
- diff = memcmp(self->data, ((PyDateTime_DateTime *)other)->data,
+ diff = memcmp(((PyDateTime_DateTime *)self)->data,
+ ((PyDateTime_DateTime *)other)->data,
_PyDateTime_DATETIME_DATASIZE);
return diff_to_bool(diff, op);
}
@@ -4568,7 +4529,7 @@
datetime_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
- (richcmpfunc)datetime_richcompare, /* tp_richcompare */
+ datetime_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
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