New submission from Keir Mierle:
This patch adds set operations & | ^ - to dict views ({}.keys(),
{}.items()). A set is returned.
----------
components: Interpreter Core
files: dictview_set_operations.diff
messages: 55280
nosy: keir
severity: normal
status: open
title: [PATCH] Add set operations (and, or, xor, subtract) to dict views
versions: Python 3.0
__________________________________
Tracker <[EMAIL PROTECTED]>
<http://bugs.python.org/issue1017>
__________________________________
Index: Objects/dictobject.c
===================================================================
--- Objects/dictobject.c (revision 57422)
+++ Objects/dictobject.c (working copy)
@@ -2489,6 +2489,97 @@
(objobjproc)dictkeys_contains, /* sq_contains */
};
+static PyObject*
+dictviews_sub(PyObject* self, PyObject *other)
+{
+ PyObject *result = PySet_New(self);
+ PyObject *tmp;
+ if (result == NULL)
+ return NULL;
+
+ tmp = PyObject_CallMethod(result, "difference_update", "O", other);
+ if (tmp == NULL) {
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ Py_DECREF(tmp);
+ return result;
+}
+
+static PyObject*
+dictviews_and(PyObject* self, PyObject *other)
+{
+ PyObject *result = PySet_New(self);
+ PyObject *tmp;
+ if (result == NULL)
+ return NULL;
+
+ tmp = PyObject_CallMethod(result, "intersection_update", "O", other);
+ if (tmp == NULL) {
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ Py_DECREF(tmp);
+ return result;
+}
+
+static PyObject*
+dictviews_or(PyObject* self, PyObject *other)
+{
+ PyObject *result = PySet_New(self);
+ PyObject *tmp;
+ if (result == NULL)
+ return NULL;
+
+ tmp = PyObject_CallMethod(result, "update", "O", other);
+ if (tmp == NULL) {
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ Py_DECREF(tmp);
+ return result;
+}
+
+static PyObject*
+dictviews_xor(PyObject* self, PyObject *other)
+{
+ PyObject *result = PySet_New(self);
+ PyObject *tmp;
+ if (result == NULL)
+ return NULL;
+
+ tmp = PyObject_CallMethod(result, "symmetric_difference_update", "O", other);
+ if (tmp == NULL) {
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ Py_DECREF(tmp);
+ return result;
+}
+
+static PyNumberMethods dictviews_as_number = {
+ 0, /*nb_add*/
+ (binaryfunc)dictviews_sub, /*nb_subtract*/
+ 0, /*nb_multiply*/
+ 0, /*nb_remainder*/
+ 0, /*nb_divmod*/
+ 0, /*nb_power*/
+ 0, /*nb_negative*/
+ 0, /*nb_positive*/
+ 0, /*nb_absolute*/
+ 0, /*nb_bool*/
+ 0, /*nb_invert*/
+ 0, /*nb_lshift*/
+ 0, /*nb_rshift*/
+ (binaryfunc)dictviews_and, /*nb_and*/
+ (binaryfunc)dictviews_xor, /*nb_xor*/
+ (binaryfunc)dictviews_or, /*nb_or*/
+};
+
static PyMethodDef dictkeys_methods[] = {
{NULL, NULL} /* sentinel */
};
@@ -2505,7 +2596,7 @@
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
- 0, /* tp_as_number */
+ &dictviews_as_number, /* tp_as_number */
&dictkeys_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
@@ -2589,7 +2680,7 @@
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
- 0, /* tp_as_number */
+ &dictviews_as_number, /* tp_as_number */
&dictitems_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
Index: Lib/test/test_dict.py
===================================================================
--- Lib/test/test_dict.py (revision 57422)
+++ Lib/test/test_dict.py (working copy)
@@ -458,6 +458,21 @@
self.assertRaises(RuntimeError, lambda: d2.items() < d3.items())
self.assertRaises(RuntimeError, lambda: d3.items() > d2.items())
+ def test_dictview_set_operations(self):
+ k1 = {1:1, 2:2}.keys()
+ k2 = {1:1, 2:2, 3:3}.keys()
+ k3 = {4:4}.keys()
+
+ self.assertEquals(k1 - k2, set())
+ self.assertEquals(k1 - k3, {1,2})
+ self.assertEquals(k2 - k1, {3})
+ self.assertEquals(k3 - k1, {4})
+ self.assertEquals(k1 & k2, {1,2})
+ self.assertEquals(k1 & k3, set())
+ self.assertEquals(k1 | k2, {1,2,3})
+ self.assertEquals(k1 ^ k2, {3})
+ self.assertEquals(k1 ^ k3, {1,2,4})
+
def test_missing(self):
# Make sure dict doesn't have a __missing__ method
self.assertEqual(hasattr(dict, "__missing__"), False)
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