Multi-arg form for set.difference() and set.difference_update().

This commit is contained in:
Raymond Hettinger 2008-06-11 10:30:54 +00:00
parent 9d53457e59
commit 4267be6478
4 changed files with 66 additions and 21 deletions

View File

@ -1583,10 +1583,13 @@ The constructors for both classes work the same:
.. versionchanged:: 2.6
Accepts multiple input iterables.
.. method:: difference(other)
set - other
.. method:: difference(other, ...)
set - other - ...
Return a new set with elements in the set that are not in *other*.
Return a new set with elements in the set that are not in the others.
.. versionchanged:: 2.6
Accepts multiple input iterables.
.. method:: symmetric_difference(other)
set ^ other
@ -1650,10 +1653,13 @@ The constructors for both classes work the same:
.. versionchanged:: 2.6
Accepts multiple input iterables.
.. method:: difference_update(other)
set -= other
.. method:: difference_update(other, ...)
set -= other | ...
Update the set, removing elements found in *other*.
Update the set, removing elements found in others.
.. versionchanged:: 2.6
Accepts multiple input iterables.
.. method:: symmetric_difference_update(other)
set ^= other

View File

@ -149,6 +149,8 @@ class TestJointOps(unittest.TestCase):
self.assertEqual(self.thetype('abcba').difference(C('efgfe')), set('abc'))
self.assertEqual(self.thetype('abcba').difference(C('ccb')), set('a'))
self.assertEqual(self.thetype('abcba').difference(C('ef')), set('abc'))
self.assertEqual(self.thetype('abcba').difference(), set('abc'))
self.assertEqual(self.thetype('abcba').difference(C('a'), C('b')), set('c'))
def test_sub(self):
i = self.s.difference(self.otherword)
@ -467,6 +469,18 @@ class TestSet(TestJointOps):
self.assertEqual(s.difference_update(C(p)), None)
self.assertEqual(s, set(q))
s = self.thetype('abcdefghih')
s.difference_update()
self.assertEqual(s, self.thetype('abcdefghih'))
s = self.thetype('abcdefghih')
s.difference_update(C('aba'))
self.assertEqual(s, self.thetype('cdefghih'))
s = self.thetype('abcdefghih')
s.difference_update(C('cdc'), C('aba'))
self.assertEqual(s, self.thetype('efghih'))
def test_isub(self):
self.s -= set(self.otherword)
for c in (self.word + self.otherword):

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@ -13,7 +13,7 @@ Core and Builtins
-----------------
- Several set methods now accept multiple arguments: update(), union(),
intersection() and intersection_update().
intersection(), intersection_update(), difference(), and difference_update().
- Issue #2898: Added sys.getsizeof() to retrieve size of objects in bytes.

View File

@ -1495,11 +1495,16 @@ set_difference_update_internal(PySetObject *so, PyObject *other)
}
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,
@ -1557,10 +1562,34 @@ set_difference(PySetObject *so, PyObject *other)
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)
{
@ -1574,16 +1603,12 @@ set_sub(PySetObject *so, PyObject *other)
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;
}
@ -1978,9 +2003,9 @@ static PyMethodDef set_methods[] = {
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},
@ -2107,7 +2132,7 @@ static PyMethodDef frozenset_methods[] = {
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},