[Python-checkins] cpython (3.5): Issue #28019: itertools.count() no longer rounds non-integer step in range
serhiy.storchaka
python-checkins at python.org
Sat Sep 10 02:54:40 EDT 2016
https://hg.python.org/cpython/rev/b23f963a7b45
changeset: 103557:b23f963a7b45
branch: 3.5
parent: 103548:427ec71e8b0e
user: Serhiy Storchaka <storchaka at gmail.com>
date: Sat Sep 10 09:49:24 2016 +0300
summary:
Issue #28019: itertools.count() no longer rounds non-integer step in range
between 1.0 and 2.0 to 1.
files:
Lib/test/test_itertools.py | 28 ++++++++++++--
Misc/NEWS | 3 +
Modules/itertoolsmodule.c | 47 ++++++++++++++++---------
3 files changed, 56 insertions(+), 22 deletions(-)
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -511,12 +511,18 @@
self.assertEqual(take(2, zip('abc',count(-3))), [('a', -3), ('b', -2)])
self.assertRaises(TypeError, count, 2, 3, 4)
self.assertRaises(TypeError, count, 'a')
- self.assertEqual(list(islice(count(maxsize-5), 10)),
+ self.assertEqual(take(10, count(maxsize-5)),
list(range(maxsize-5, maxsize+5)))
- self.assertEqual(list(islice(count(-maxsize-5), 10)),
+ self.assertEqual(take(10, count(-maxsize-5)),
list(range(-maxsize-5, -maxsize+5)))
- self.assertEqual(list(islice(count(10, maxsize+5), 3)),
- list(range(10, 10+3*(maxsize+5), maxsize+5)))
+ self.assertEqual(take(3, count(3.25)), [3.25, 4.25, 5.25])
+ self.assertEqual(take(3, count(3.25-4j)), [3.25-4j, 4.25-4j, 5.25-4j])
+ self.assertEqual(take(3, count(Decimal('1.1'))),
+ [Decimal('1.1'), Decimal('2.1'), Decimal('3.1')])
+ self.assertEqual(take(3, count(Fraction(2, 3))),
+ [Fraction(2, 3), Fraction(5, 3), Fraction(8, 3)])
+ BIGINT = 1<<1000
+ self.assertEqual(take(3, count(BIGINT)), [BIGINT, BIGINT+1, BIGINT+2])
c = count(3)
self.assertEqual(repr(c), 'count(3)')
next(c)
@@ -524,8 +530,10 @@
c = count(-9)
self.assertEqual(repr(c), 'count(-9)')
next(c)
+ self.assertEqual(next(c), -8)
self.assertEqual(repr(count(10.25)), 'count(10.25)')
- self.assertEqual(next(c), -8)
+ self.assertEqual(repr(count(10.0)), 'count(10.0)')
+ self.assertEqual(type(next(count(10.0))), float)
for i in (-sys.maxsize-5, -sys.maxsize+5 ,-10, -1, 0, 10, sys.maxsize-5, sys.maxsize+5):
# Test repr
r1 = repr(count(i))
@@ -549,16 +557,22 @@
[('a', 2), ('b', 5), ('c', 8)])
self.assertEqual(lzip('abc',count(step=-1)),
[('a', 0), ('b', -1), ('c', -2)])
+ self.assertRaises(TypeError, count, 'a', 'b')
self.assertEqual(lzip('abc',count(2,0)), [('a', 2), ('b', 2), ('c', 2)])
self.assertEqual(lzip('abc',count(2,1)), [('a', 2), ('b', 3), ('c', 4)])
self.assertEqual(lzip('abc',count(2,3)), [('a', 2), ('b', 5), ('c', 8)])
self.assertEqual(take(20, count(maxsize-15, 3)), take(20, range(maxsize-15, maxsize+100, 3)))
self.assertEqual(take(20, count(-maxsize-15, 3)), take(20, range(-maxsize-15,-maxsize+100, 3)))
+ self.assertEqual(take(3, count(10, maxsize+5)),
+ list(range(10, 10+3*(maxsize+5), maxsize+5)))
+ self.assertEqual(take(3, count(2, 1.25)), [2, 3.25, 4.5])
self.assertEqual(take(3, count(2, 3.25-4j)), [2, 5.25-4j, 8.5-8j])
self.assertEqual(take(3, count(Decimal('1.1'), Decimal('.1'))),
[Decimal('1.1'), Decimal('1.2'), Decimal('1.3')])
self.assertEqual(take(3, count(Fraction(2,3), Fraction(1,7))),
[Fraction(2,3), Fraction(17,21), Fraction(20,21)])
+ BIGINT = 1<<1000
+ self.assertEqual(take(3, count(step=BIGINT)), [0, BIGINT, 2*BIGINT])
self.assertEqual(repr(take(3, count(10, 2.5))), repr([10, 12.5, 15.0]))
c = count(3, 5)
self.assertEqual(repr(c), 'count(3, 5)')
@@ -576,6 +590,10 @@
self.assertEqual(repr(count(10.5, 1.25)), 'count(10.5, 1.25)')
self.assertEqual(repr(count(10.5, 1)), 'count(10.5)') # suppress step=1 when it's an int
self.assertEqual(repr(count(10.5, 1.00)), 'count(10.5, 1.0)') # do show float values lilke 1.0
+ self.assertEqual(repr(count(10, 1.00)), 'count(10, 1.0)')
+ c = count(10, 1.0)
+ self.assertEqual(type(next(c)), int)
+ self.assertEqual(type(next(c)), float)
for i in (-sys.maxsize-5, -sys.maxsize+5 ,-10, -1, 0, 10, sys.maxsize-5, sys.maxsize+5):
for j in (-sys.maxsize-5, -sys.maxsize+5 ,-10, -1, 0, 1, 10, sys.maxsize-5, sys.maxsize+5):
# Test repr
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -65,6 +65,9 @@
Library
-------
+- Issue #28019: itertools.count() no longer rounds non-integer step in range
+ between 1.0 and 2.0 to 1.
+
- Issue #25969: Update the lib2to3 grammar to handle the unpacking
generalizations added in 3.5.
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -3905,7 +3905,7 @@
count_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
countobject *lz;
- int slow_mode = 0;
+ int fast_mode;
Py_ssize_t cnt = 0;
PyObject *long_cnt = NULL;
PyObject *long_step = NULL;
@@ -3922,16 +3922,26 @@
return NULL;
}
+ fast_mode = (long_cnt == NULL || PyLong_Check(long_cnt)) &&
+ (long_step == NULL || PyLong_Check(long_step));
+
+ /* If not specified, start defaults to 0 */
if (long_cnt != NULL) {
- cnt = PyLong_AsSsize_t(long_cnt);
- if ((cnt == -1 && PyErr_Occurred()) || !PyLong_Check(long_cnt)) {
- PyErr_Clear();
- slow_mode = 1;
+ if (fast_mode) {
+ assert(PyLong_Check(long_cnt));
+ cnt = PyLong_AsSsize_t(long_cnt);
+ if (cnt == -1 && PyErr_Occurred()) {
+ PyErr_Clear();
+ fast_mode = 0;
+ }
}
Py_INCREF(long_cnt);
} else {
cnt = 0;
long_cnt = PyLong_FromLong(0);
+ if (long_cnt == NULL) {
+ return NULL;
+ }
}
/* If not specified, step defaults to 1 */
@@ -3947,21 +3957,24 @@
assert(long_cnt != NULL && long_step != NULL);
/* Fast mode only works when the step is 1 */
- step = PyLong_AsLong(long_step);
- if (step != 1) {
- slow_mode = 1;
- if (step == -1 && PyErr_Occurred())
- PyErr_Clear();
+ if (fast_mode) {
+ assert(PyLong_Check(long_step));
+ step = PyLong_AsLong(long_step);
+ if (step != 1) {
+ fast_mode = 0;
+ if (step == -1 && PyErr_Occurred())
+ PyErr_Clear();
+ }
}
- if (slow_mode)
+ if (fast_mode)
+ Py_CLEAR(long_cnt);
+ else
cnt = PY_SSIZE_T_MAX;
- else
- Py_CLEAR(long_cnt);
-
- assert((cnt != PY_SSIZE_T_MAX && long_cnt == NULL && !slow_mode) ||
- (cnt == PY_SSIZE_T_MAX && long_cnt != NULL && slow_mode));
- assert(slow_mode ||
+
+ assert((cnt != PY_SSIZE_T_MAX && long_cnt == NULL && fast_mode) ||
+ (cnt == PY_SSIZE_T_MAX && long_cnt != NULL && !fast_mode));
+ assert(!fast_mode ||
(PyLong_Check(long_step) && PyLong_AS_LONG(long_step) == 1));
/* create countobject structure */
--
Repository URL: https://hg.python.org/cpython
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