[Python-checkins] cpython: Issue 19933: Provide default argument for ndigits in round. Patch by Vajrasky

Wed Apr 15 22:16:17 CEST 2015

https://hg.python.org/cpython/rev/e3cc75b1000b
changeset: 95678:e3cc75b1000b
user: Steve Dower <steve.dower at microsoft.com>
date: Wed Apr 15 16:10:59 2015 -0400
summary:
 Issue 19933: Provide default argument for ndigits in round. Patch by Vajrasky Kok.
files:
 Doc/library/functions.rst | 4 ++--
 Lib/test/test_float.py | 8 ++++++++
 Misc/NEWS | 3 +++
 Objects/floatobject.c | 5 +++--
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1225,8 +1225,8 @@
 .. function:: round(number[, ndigits])
 
 Return the floating point value *number* rounded to *ndigits* digits after
- the decimal point. If *ndigits* is omitted, it defaults to zero. Delegates
- to ``number.__round__(ndigits)``.
+ the decimal point. If *ndigits* is omitted, it returns the nearest integer
+ to its input. Delegates to ``number.__round__(ndigits)``.
 
 For the built-in types supporting :func:`round`, values are rounded to the
 closest multiple of 10 to the power minus *ndigits*; if two multiples are
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -773,6 +773,14 @@
 test(sfmt, NAN, ' nan')
 test(sfmt, -NAN, ' nan')
 
+ def test_None_ndigits(self):
+ for x in round(1.23), round(1.23, None), round(1.23, ndigits=None):
+ self.assertEqual(x, 1)
+ self.assertIsInstance(x, int)
+ for x in round(1.78), round(1.78, None), round(1.78, ndigits=None):
+ self.assertEqual(x, 2)
+ self.assertIsInstance(x, int)
+
 
 # Beginning with Python 2.6 float has cross platform compatible
 # ways to create and represent inf and nan
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -36,6 +36,9 @@
 Library
 -------
 
+- Issue 19933: Provide default argument for ndigits in round. Patch by
+ Vajrasky Kok.
+
 - Issue #23193: Add a numeric_owner parameter to
 tarfile.TarFile.extract and tarfile.TarFile.extractall. Patch by
 Michael Vogt and Eric Smith.
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -986,8 +986,9 @@
 x = PyFloat_AsDouble(v);
 if (!PyArg_ParseTuple(args, "|O", &o_ndigits))
 return NULL;
- if (o_ndigits == NULL) {
- /* single-argument round: round to nearest integer */
+ if (o_ndigits == NULL || o_ndigits == Py_None) {
+ /* single-argument round or with None ndigits:
+ * round to nearest integer */
 rounded = round(x);
 if (fabs(x-rounded) == 0.5)
 /* halfway case: round to even */
-- 
Repository URL: https://hg.python.org/cpython
