Merged revisions 64089,64098,64100-64102,64113,64115-64116,64118,64120,64132,64342 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

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  r64089 | armin.ronacher | 2008-06-10 22:37:02 +0200 (mar., 10 juin 2008) | 3 lines

  Fix a formatting error in the ast documentation.
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  r64098 | raymond.hettinger | 2008-06-11 02:25:29 +0200 (mer., 11 juin 2008) | 6 lines

  Mini-PEP: Simplifying numbers.py
  * Convert binary methods in Integral to mixin methods
  * Remove three-arg __pow__ as a required method
  * Make __int__ the root method instead of __long__.
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  r64100 | raymond.hettinger | 2008-06-11 02:28:51 +0200 (mer., 11 juin 2008) | 1 line

  Update numbers doc for the Integral simplification.
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  r64101 | raymond.hettinger | 2008-06-11 02:44:47 +0200 (mer., 11 juin 2008) | 3 lines

  Handle the case with zero arguments.
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  r64102 | benjamin.peterson | 2008-06-11 03:31:28 +0200 (mer., 11 juin 2008) | 4 lines

  convert test_struct to a unittest thanks to Giampaolo Rodola
  I had to disable one test because it was functioning incorrectly, see #1530559
  I also removed the debugging prints
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  r64113 | thomas.heller | 2008-06-11 09:10:43 +0200 (mer., 11 juin 2008) | 2 lines

  Fix markup.
  Document the new 'offset' parameter for the 'ctypes.byref' function.
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  r64115 | raymond.hettinger | 2008-06-11 12:30:54 +0200 (mer., 11 juin 2008) | 1 line

  Multi-arg form for set.difference() and set.difference_update().
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  r64116 | raymond.hettinger | 2008-06-11 14:06:49 +0200 (mer., 11 juin 2008) | 1 line

  Issue 3051:  Let heapq work with either __lt__ or __le__.
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  r64118 | raymond.hettinger | 2008-06-11 14:39:09 +0200 (mer., 11 juin 2008) | 1 line

  Optimize previous checkin for heapq.
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  r64120 | raymond.hettinger | 2008-06-11 15:14:50 +0200 (mer., 11 juin 2008) | 1 line

  Add test for heapq using both __lt__ and __le__.
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  r64132 | gregory.p.smith | 2008-06-11 20:00:52 +0200 (mer., 11 juin 2008) | 3 lines

  Correct an incorrect comment about our #include of stddef.h.
  (see Doug Evans' comment on python-dev 2008-06-10)
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  r64342 | guido.van.rossum | 2008-06-17 19:38:02 +0200 (mar., 17 juin 2008) | 3 lines

  Roll back Raymond's -r64098 while we think of something better.
  (See issue 3056 -- we're close to a resolution but need unittests.)
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diff --git a/Objects/setobject.c b/Objects/setobject.c
index e5c89e5..461fee6 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1304,6 +1304,9 @@
 	Py_ssize_t i;
 	PyObject *result = (PyObject *)so;
 
+	if (PyTuple_GET_SIZE(args) == 0)
+		return set_copy(so);
+
 	Py_INCREF(so);
 	for (i=0 ; i<PyTuple_GET_SIZE(args) ; i++) {
 		PyObject *other = PyTuple_GET_ITEM(args, i);
@@ -1484,11 +1487,16 @@
 }
 
 static PyObject *
-set_difference_update(PySetObject *so, PyObject *other)
+set_difference_update(PySetObject *so, PyObject *args)
 {
-	if (set_difference_update_internal(so, other) != -1)
-		Py_RETURN_NONE;
-	return NULL;
+	Py_ssize_t i;
+
+	for (i=0 ; i<PyTuple_GET_SIZE(args) ; i++) {
+		PyObject *other = PyTuple_GET_ITEM(args, i);
+		if (set_difference_update_internal(so, other) == -1)
+			return NULL;
+	}
+	Py_RETURN_NONE;
 }
 
 PyDoc_STRVAR(difference_update_doc,
@@ -1546,10 +1554,34 @@
 	return result;
 }
 
+static PyObject *
+set_difference_multi(PySetObject *so, PyObject *args)
+{
+	Py_ssize_t i;
+	PyObject *result, *other;
+
+	if (PyTuple_GET_SIZE(args) == 0)
+		return set_copy(so);
+
+	other = PyTuple_GET_ITEM(args, 0);
+	result = set_difference(so, other);
+	if (result == NULL)
+		return NULL;
+
+	for (i=1 ; i<PyTuple_GET_SIZE(args) ; i++) {
+		other = PyTuple_GET_ITEM(args, i);
+		if (set_difference_update_internal((PySetObject *)result, other) == -1) {
+			Py_DECREF(result);
+			return NULL;
+		}
+	}
+	return result;
+}
+
 PyDoc_STRVAR(difference_doc,
-"Return the difference of two sets as a new set.\n\
+"Return the difference of two or more sets as a new set.\n\
 \n\
-(i.e. all elements that are in this set but not the other.)");
+(i.e. all elements that are in this set but not the others.)");
 static PyObject *
 set_sub(PySetObject *so, PyObject *other)
 {
@@ -1563,16 +1595,12 @@
 static PyObject *
 set_isub(PySetObject *so, PyObject *other)
 {
-	PyObject *result;
-
 	if (!PyAnySet_Check(other)) {
 		Py_INCREF(Py_NotImplemented);
 		return Py_NotImplemented;
 	}
-	result = set_difference_update(so, other);
-	if (result == NULL)
+	if (set_difference_update_internal(so, other) == -1)
 		return NULL;
-	Py_DECREF(result);
 	Py_INCREF(so);
 	return (PyObject *)so;
 }
@@ -1963,9 +1991,9 @@
 	 copy_doc},
 	{"discard",	(PyCFunction)set_discard,	METH_O,
 	 discard_doc},
-	{"difference",	(PyCFunction)set_difference,	METH_O,
+	{"difference",	(PyCFunction)set_difference_multi,	METH_VARARGS,
 	 difference_doc},
-	{"difference_update",	(PyCFunction)set_difference_update,	METH_O,
+	{"difference_update",	(PyCFunction)set_difference_update,	METH_VARARGS,
 	 difference_update_doc},
 	{"intersection",(PyCFunction)set_intersection_multi,	METH_VARARGS,
 	 intersection_doc},
@@ -2087,7 +2115,7 @@
 	 contains_doc},
 	{"copy",	(PyCFunction)frozenset_copy,	METH_NOARGS,
 	 copy_doc},
-	{"difference",	(PyCFunction)set_difference,	METH_O,
+	{"difference",	(PyCFunction)set_difference_multi,	METH_VARARGS,
 	 difference_doc},
 	{"intersection",(PyCFunction)set_intersection_multi,	METH_VARARGS,
 	 intersection_doc},