[Python-checkins] cpython (merge default -> default): Merge heads

[petri.lehtinen]

http://hg.python.org/cpython/rev/3f22e4f4c761
changeset:   73382:3f22e4f4c761
parent:      73381:f853a2cbd68b
parent:      73379:91d59ccf1e4d
user:        Petri Lehtinen <petri at digip.org>
date:        Sat Nov 05 22:00:14 2011 +0200
summary:
  Merge heads

files:
  Doc/library/functions.rst |   7 +++++-
  Lib/test/test_range.py    |  29 +++++++++++++++++++++++++++
  Misc/NEWS                 |   2 +
  Objects/rangeobject.c     |  10 ++++++++-
  4 files changed, 46 insertions(+), 2 deletions(-)


diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1042,7 +1042,9 @@
    ...]``.  If *step* is positive, the last element is the largest ``start + i *
    step`` less than *stop*; if *step* is negative, the last element is the
    smallest ``start + i * step`` greater than *stop*.  *step* must not be zero
-   (or else :exc:`ValueError` is raised).  Example:
+   (or else :exc:`ValueError` is raised).  Range objects have read-only data
+   attributes :attr:`start`, :attr:`stop` and :attr:`step` which return the
+   argument values (or their default).  Example:
 
       >>> list(range(10))
       [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
@@ -1100,6 +1102,9 @@
       sequence of values they define (instead of comparing based on
       object identity).
 
+   .. versionadded:: 3.3
+      The :attr:`start`, :attr:`stop` and :attr:`step` attributes.
+
 
 .. function:: repr(object)
 
diff --git a/Lib/test/test_range.py b/Lib/test/test_range.py
--- a/Lib/test/test_range.py
+++ b/Lib/test/test_range.py
@@ -560,6 +560,35 @@
             range(0) >= range(0)
 
 
+    def test_attributes(self):
+        # test the start, stop and step attributes of range objects
+        self.assert_attrs(range(0), 0, 0, 1)
+        self.assert_attrs(range(10), 0, 10, 1)
+        self.assert_attrs(range(-10), 0, -10, 1)
+        self.assert_attrs(range(0, 10, 1), 0, 10, 1)
+        self.assert_attrs(range(0, 10, 3), 0, 10, 3)
+        self.assert_attrs(range(10, 0, -1), 10, 0, -1)
+        self.assert_attrs(range(10, 0, -3), 10, 0, -3)
+
+    def assert_attrs(self, rangeobj, start, stop, step):
+        self.assertEqual(rangeobj.start, start)
+        self.assertEqual(rangeobj.stop, stop)
+        self.assertEqual(rangeobj.step, step)
+
+        with self.assertRaises(AttributeError):
+            rangeobj.start = 0
+        with self.assertRaises(AttributeError):
+            rangeobj.stop = 10
+        with self.assertRaises(AttributeError):
+            rangeobj.step = 1
+
+        with self.assertRaises(AttributeError):
+            del rangeobj.start
+        with self.assertRaises(AttributeError):
+            del rangeobj.stop
+        with self.assertRaises(AttributeError):
+            del rangeobj.step
+
 def test_main():
     test.support.run_unittest(RangeTest)
 
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,8 @@
 Core and Builtins
 -----------------
 
+- Issue #9896: Add start, stop, and step attributes to range objects.
+
 - Issue #13343: Fix a SystemError when a lambda expression uses a global
   variable in the default value of a keyword-only argument:
   (lambda *, arg=GLOBAL_NAME: None)
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -1,6 +1,7 @@
 /* Range object implementation */
 
 #include "Python.h"
+#include "structmember.h"
 
 /* Support objects whose length is > PY_SSIZE_T_MAX.
 
@@ -880,6 +881,13 @@
     {NULL,              NULL}           /* sentinel */
 };
 
+static PyMemberDef range_members[] = {
+    {"start",   T_OBJECT_EX,    offsetof(rangeobject, start),   READONLY},
+    {"stop",    T_OBJECT_EX,    offsetof(rangeobject, stop),    READONLY},
+    {"step",    T_OBJECT_EX,    offsetof(rangeobject, step),    READONLY},
+    {0}
+};
+
 PyTypeObject PyRange_Type = {
         PyVarObject_HEAD_INIT(&PyType_Type, 0)
         "range",                /* Name of this type */
@@ -909,7 +917,7 @@
         range_iter,             /* tp_iter */
         0,                      /* tp_iternext */
         range_methods,          /* tp_methods */
-        0,                      /* tp_members */
+        range_members,          /* tp_members */
         0,                      /* tp_getset */
         0,                      /* tp_base */
         0,                      /* tp_dict */

-- 
Repository URL: http://hg.python.org/cpython