[Python-checkins] r61028 - in python/trunk: Doc/library/operator.rst Lib/test/test_operator.py Misc/NEWS Modules/operator.c
georg.brandl
python-checkins at python.org
Sun Feb 24 00:04:36 CET 2008
Author: georg.brandl
Date: Sun Feb 24 00:04:35 2008
New Revision: 61028
Modified:
python/trunk/Doc/library/operator.rst
python/trunk/Lib/test/test_operator.py
python/trunk/Misc/NEWS
python/trunk/Modules/operator.c
Log:
#1506171: added operator.methodcaller().
Modified: python/trunk/Doc/library/operator.rst
==============================================================================
--- python/trunk/Doc/library/operator.rst (original)
+++ python/trunk/Doc/library/operator.rst Sun Feb 24 00:04:35 2008
@@ -538,6 +538,17 @@
[('orange', 1), ('banana', 2), ('apple', 3), ('pear', 5)]
+.. function:: methodcaller(name[, args...])
+
+ Return a callable object that calls the method *name* on its operand. If
+ additional arguments and/or keyword arguments are given, they will be given
+ to the method as well. After ``f = methodcaller('name')``, the call ``f(b)``
+ returns ``b.name()``. After ``f = methodcaller('name', 'foo', bar=1)``, the
+ call ``f(b)`` returns ``b.name('foo', bar=1)``.
+
+ .. versionadded:: 2.6
+
+
.. _operator-map:
Mapping Operators to Functions
Modified: python/trunk/Lib/test/test_operator.py
==============================================================================
--- python/trunk/Lib/test/test_operator.py (original)
+++ python/trunk/Lib/test/test_operator.py Sun Feb 24 00:04:35 2008
@@ -440,6 +440,24 @@
self.assertEqual(operator.itemgetter(2,10,5)(data), ('2', '10', '5'))
self.assertRaises(TypeError, operator.itemgetter(2, 'x', 5), data)
+ def test_methodcaller(self):
+ self.assertRaises(TypeError, operator.methodcaller)
+ class A:
+ def foo(self, *args, **kwds):
+ return args[0] + args[1]
+ def bar(self, f=42):
+ return f
+ a = A()
+ f = operator.methodcaller('foo')
+ self.assertRaises(IndexError, f, a)
+ f = operator.methodcaller('foo', 1, 2)
+ self.assertEquals(f(a), 3)
+ f = operator.methodcaller('bar')
+ self.assertEquals(f(a), 42)
+ self.assertRaises(TypeError, f, a, a)
+ f = operator.methodcaller('bar', f=5)
+ self.assertEquals(f(a), 5)
+
def test_inplace(self):
class C(object):
def __iadd__ (self, other): return "iadd"
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Sun Feb 24 00:04:35 2008
@@ -1196,6 +1196,8 @@
Extension Modules
-----------------
+- Patch #1506171: added operator.methodcaller().
+
- Patch #1826: operator.attrgetter() now supports dotted attribute paths.
- Patch #1957: syslogmodule: Release GIL when calling syslog(3)
Modified: python/trunk/Modules/operator.c
==============================================================================
--- python/trunk/Modules/operator.c (original)
+++ python/trunk/Modules/operator.c Sun Feb 24 00:04:35 2008
@@ -620,6 +620,139 @@
attrgetter_new, /* tp_new */
0, /* tp_free */
};
+
+
+/* methodcaller object **********************************************************/
+
+typedef struct {
+ PyObject_HEAD
+ PyObject *name;
+ PyObject *args;
+ PyObject *kwds;
+} methodcallerobject;
+
+static PyTypeObject methodcaller_type;
+
+static PyObject *
+methodcaller_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+ methodcallerobject *mc;
+ PyObject *name, *newargs;
+
+ if (PyTuple_GET_SIZE(args) < 1) {
+ PyErr_SetString(PyExc_TypeError, "methodcaller needs at least "
+ "one argument, the method name");
+ return NULL;
+ }
+
+ /* create methodcallerobject structure */
+ mc = PyObject_GC_New(methodcallerobject, &methodcaller_type);
+ if (mc == NULL)
+ return NULL;
+
+ newargs = PyTuple_GetSlice(args, 1, PyTuple_GET_SIZE(args));
+ if (newargs == NULL) {
+ Py_DECREF(mc);
+ return NULL;
+ }
+ mc->args = newargs;
+
+ name = PyTuple_GET_ITEM(args, 0);
+ Py_INCREF(name);
+ mc->name = name;
+
+ Py_XINCREF(kwds);
+ mc->kwds = kwds;
+
+ PyObject_GC_Track(mc);
+ return (PyObject *)mc;
+}
+
+static void
+methodcaller_dealloc(methodcallerobject *mc)
+{
+ PyObject_GC_UnTrack(mc);
+ Py_XDECREF(mc->name);
+ Py_XDECREF(mc->args);
+ Py_XDECREF(mc->kwds);
+ PyObject_GC_Del(mc);
+}
+
+static int
+methodcaller_traverse(methodcallerobject *mc, visitproc visit, void *arg)
+{
+ Py_VISIT(mc->args);
+ Py_VISIT(mc->kwds);
+ return 0;
+}
+
+static PyObject *
+methodcaller_call(methodcallerobject *mc, PyObject *args, PyObject *kw)
+{
+ PyObject *method, *obj, *result;
+
+ if (!PyArg_UnpackTuple(args, "methodcaller", 1, 1, &obj))
+ return NULL;
+ method = PyObject_GetAttr(obj, mc->name);
+ if (method == NULL)
+ return NULL;
+ result = PyObject_Call(method, mc->args, mc->kwds);
+ Py_DECREF(method);
+ return result;
+}
+
+PyDoc_STRVAR(methodcaller_doc,
+"methodcaller(name, ...) --> methodcaller object\n\
+\n\
+Return a callable object that calls the given method on its operand.\n\
+After, f = methodcaller('name'), the call f(r) returns r.name().\n\
+After, g = methodcaller('name', 'date', foo=1), the call g(r) returns\n\
+r.name('date', foo=1).");
+
+static PyTypeObject methodcaller_type = {
+ PyVarObject_HEAD_INIT(NULL, 0)
+ "operator.methodcaller", /* tp_name */
+ sizeof(methodcallerobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)methodcaller_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ (ternaryfunc)methodcaller_call, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+ methodcaller_doc, /* tp_doc */
+ (traverseproc)methodcaller_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ 0, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ 0, /* tp_alloc */
+ methodcaller_new, /* tp_new */
+ 0, /* tp_free */
+};
+
+
/* Initialization function for the module (*must* be called initoperator) */
PyMODINIT_FUNC
@@ -642,4 +775,9 @@
return;
Py_INCREF(&attrgetter_type);
PyModule_AddObject(m, "attrgetter", (PyObject *)&attrgetter_type);
+
+ if (PyType_Ready(&methodcaller_type) < 0)
+ return;
+ Py_INCREF(&methodcaller_type);
+ PyModule_AddObject(m, "methodcaller", (PyObject *)&methodcaller_type);
}
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