SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
method for constructing new dictionaries from sequences of keys.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 2eaa20c..b8ba7e1 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -963,6 +963,56 @@
}
static PyObject *
+dict_fromkeys(PyObject *mp, PyObject *args)
+{
+ PyObject *seq;
+ PyObject *value = Py_None;
+ PyObject *it; /* iter(seq) */
+ PyObject *key;
+ PyObject *d;
+ PyObject *cls;
+ int status;
+
+ if (!PyArg_ParseTuple(args, "OO|O:fromkeys", &cls, &seq, &value))
+ return NULL;
+
+ d = PyObject_CallObject(cls, NULL);
+ if (d == NULL)
+ return NULL;
+ if (!PyDict_Check(d)) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+
+ it = PyObject_GetIter(seq);
+ if (it == NULL){
+ Py_DECREF(d);
+ return NULL;
+ }
+
+ for (;;) {
+ key = PyIter_Next(it);
+ if (key == NULL) {
+ if (PyErr_Occurred())
+ goto Fail;
+ break;
+ }
+ status = PyDict_SetItem(d, key, value);
+ Py_DECREF(key);
+ if (status < 0)
+ goto Fail;
+ }
+
+ Py_DECREF(it);
+ return d;
+
+Fail:
+ Py_DECREF(it);
+ Py_DECREF(d);
+ return NULL;
+}
+
+static PyObject *
dict_update(PyObject *mp, PyObject *other)
{
if (PyDict_Update(mp, other) < 0)
@@ -1682,6 +1732,10 @@
PyDoc_STRVAR(update__doc__,
"D.update(E) -> None. Update D from E: for k in E.keys(): D[k] = E[k]");
+PyDoc_STRVAR(fromkeys__doc__,
+"dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.\n\
+v defaults to None.");
+
PyDoc_STRVAR(clear__doc__,
"D.clear() -> None. Remove all items from D.");
@@ -1716,6 +1770,8 @@
values__doc__},
{"update", (PyCFunction)dict_update, METH_O,
update__doc__},
+ {"fromkeys", (PyCFunction)dict_fromkeys, METH_VARARGS | METH_CLASS,
+ fromkeys__doc__},
{"clear", (PyCFunction)dict_clear, METH_NOARGS,
clear__doc__},
{"copy", (PyCFunction)dict_copy, METH_NOARGS,