Minor improvements to itertools.tee():
* tee object is no longer subclassable
* independent iterators renamed to "itertools.tee_iterator"
* fixed doc string typo and added entry in the module doc string
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index ce03b1a..e12aa41 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -243,6 +243,18 @@
self.assertRaises(TypeError, tee, 3)
self.assertRaises(TypeError, tee, [1,2], 'x')
+ try:
+ class A(tee): pass
+ except TypeError:
+ pass
+ else:
+ self.fail("tee constructor should not be subclassable")
+
+ # tee_iterator should not be instantiable
+ a, b = tee(xrange(10))
+ self.assertRaises(TypeError, type(a))
+ self.assert_(a is iter(a)) # tee_iterator should support __iter__
+
def test_StopIteration(self):
self.assertRaises(StopIteration, izip().next)
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index b37dec1..7cafc14 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -113,12 +113,12 @@
return 0;
}
-PyDoc_STRVAR(ii_doc, "Independent iterators linked to a tee() object.");
+PyDoc_STRVAR(ii_doc, "Independent iterator created by tee(iterable).");
static PyTypeObject ii_type = {
PyObject_HEAD_INIT(&PyType_Type)
0, /* ob_size */
- "itertools.independent_iterator", /* tp_name */
+ "itertools.tee_iterator", /* tp_name */
sizeof(iiobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
@@ -173,7 +173,7 @@
outbasket = PyList_New(0);
if (outbasket == NULL) goto fail;
- to = (teeobject *)type->tp_alloc(type, 0);
+ to = PyObject_GC_New(teeobject, &tee_type);
if (to == NULL) goto fail;
to->it = it;
@@ -181,6 +181,7 @@
to->outbasket = outbasket;
to->save_mode = 1;
to->num_seen = 0;
+ PyObject_GC_Track(to);
/* create independent iterators */
result = PyTuple_New(2);
@@ -212,7 +213,7 @@
Py_XDECREF(to->inbasket);
Py_XDECREF(to->outbasket);
Py_XDECREF(to->it);
- to->ob_type->tp_free(to);
+ PyObject_GC_Del(to);
}
static int
@@ -241,7 +242,7 @@
PyDoc_STRVAR(tee_doc,
"tee(iterable) --> (it1, it2)\n\
\n\
-Split the iterable into to independent iterables.");
+Split the iterable into two independent iterables.");
static PyTypeObject tee_type = {
PyObject_HEAD_INIT(NULL)
@@ -262,11 +263,10 @@
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
- PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
- Py_TPFLAGS_BASETYPE, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
tee_doc, /* tp_doc */
(traverseproc)tee_traverse, /* tp_traverse */
0, /* tp_clear */
@@ -285,7 +285,6 @@
0, /* tp_init */
0, /* tp_alloc */
tee_new, /* tp_new */
- PyObject_GC_Del, /* tp_free */
};
/* cycle object **********************************************************/
@@ -2092,6 +2091,7 @@
seq[start:stop:step]\n\
imap(fun, p, q, ...) --> fun(p0, q0), fun(p1, q1), ...\n\
starmap(fun, seq) --> fun(*seq[0]), fun(*seq[1]), ...\n\
+tee(it) --> (it1, it2) splits one iterator into two \n\
chain(p, q, ...) --> p0, p1, ... plast, q0, q1, ... \n\
takewhile(pred, seq) --> seq[0], seq[1], until pred fails\n\
dropwhile(pred, seq) --> seq[n], seq[n+1], starting when pred fails\n\