diff -r 8a5bebea9fec Modules/itertoolsmodule.c
--- a/Modules/itertoolsmodule.c	Wed May 08 13:23:25 2013 +0200
+++ b/Modules/itertoolsmodule.c	Wed May 08 18:39:25 2013 +0300
@@ -4446,6 +4446,166 @@
     PyObject_GC_Del,                    /* tp_free */
 };
 
+/* chunks object ************************************************************/
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *seq;
+    Py_ssize_t size;
+    Py_ssize_t index;
+} chunksobject;
+
+static PyTypeObject chunks_type;
+
+static PyObject *
+chunks_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+    PyObject *seq;
+    Py_ssize_t size, start = 0;
+    chunksobject *co;
+    static char *kwargs[] = {"seq", "size", "start", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "On|n:chunks", kwargs,
+                                     &seq, &size, &start))
+        return NULL;
+
+    if (size <= 0) {
+        PyErr_Format(PyExc_ValueError, "size must be > 0");
+        return NULL;
+    }
+
+    if (start < 0) {
+        PyErr_Format(PyExc_ValueError, "start must be >= 0");
+        return NULL;
+    }
+
+    /* create chunksobject structure */
+    co = (chunksobject *)type->tp_alloc(type, 0);
+    if (co == NULL) {
+        Py_DECREF(seq);
+        return NULL;
+    }
+    Py_INCREF(seq);
+    co->seq = seq;
+    co->size = size;
+    co->index = start;
+
+    return (PyObject *)co;
+}
+
+static void
+chunks_dealloc(chunksobject *co)
+{
+    PyObject_GC_UnTrack(co);
+    Py_XDECREF(co->seq);
+    Py_TYPE(co)->tp_free(co);
+}
+
+static int
+chunks_traverse(chunksobject *co, visitproc visit, void *arg)
+{
+    Py_VISIT(co->seq);
+    return 0;
+}
+
+static PyObject *
+chunks_next(chunksobject *co)
+{
+    PyObject *chunk;
+    Py_ssize_t next, size;
+
+    if (co->index > PY_SIZE_MAX - co->size)
+        next = PY_SIZE_MAX;
+    else
+        next = co->index + co->size;
+
+    chunk = PySequence_GetSlice(co->seq, co->index, next);
+    if (chunk == NULL)
+        return NULL;
+
+    size = PySequence_Size(chunk);
+    if (size <= 0) {
+        /* an error or end of iteration */
+        Py_DECREF(chunk);
+        return NULL;
+    }
+
+    co->index = next;
+    return chunk;
+}
+
+static PyObject *
+chunks_len(chunksobject *co)
+{
+    Py_ssize_t size = PySequence_Size(co->seq);
+    if (size == -1 && PyErr_Occurred())
+        return NULL;
+    return PyLong_FromSize_t(size / co->size);
+}
+
+static PyObject *
+chunks_reduce(chunksobject *co)
+{
+    return Py_BuildValue("O(Onn)", Py_TYPE(co),
+        co->seq, co->size, co->index);
+}
+
+static PyMethodDef chunks_methods[] = {
+    {"__length_hint__", (PyCFunction)chunks_len, METH_NOARGS, length_hint_doc},
+    {"__reduce__",      (PyCFunction)chunks_reduce, METH_NOARGS, reduce_doc},
+    {NULL,              NULL}   /* sentinel */
+};
+
+PyDoc_STRVAR(chunks_doc,
+"chunks(sequence, size, [start]) --> chunks iterator\n\
+\n\
+Split a sequence on chunks of specified size:\n\
+sequence[start: start + size], sequence[start + size: start + 2*size],..");
+
+static PyTypeObject chunks_type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "itertools.chunks",                 /* tp_name */
+    sizeof(chunksobject),               /* tp_basicsize */
+    0,                                  /* tp_itemsize */
+    /* methods */
+    (destructor)chunks_dealloc,         /* tp_dealloc */
+    0,                                  /* tp_print */
+    0,                                  /* tp_getattr */
+    0,                                  /* tp_setattr */
+    0,                                  /* tp_reserved */
+    0,                                  /* tp_repr */
+    0,                                  /* tp_as_number */
+    0,                                  /* tp_as_sequence */
+    0,                                  /* tp_as_mapping */
+    0,                                  /* tp_hash */
+    0,                                  /* tp_call */
+    0,                                  /* tp_str */
+    PyObject_GenericGetAttr,            /* tp_getattro */
+    0,                                  /* tp_setattro */
+    0,                                  /* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+        Py_TPFLAGS_BASETYPE,            /* tp_flags */
+    chunks_doc,                         /* tp_doc */
+    (traverseproc)chunks_traverse,      /* tp_traverse */
+    0,                                  /* tp_clear */
+    0,                                  /* tp_richcompare */
+    0,                                  /* tp_weaklistoffset */
+    PyObject_SelfIter,                  /* tp_iter */
+    (iternextfunc)chunks_next,          /* tp_iternext */
+    chunks_methods,                     /* 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 */
+    chunks_new,                         /* tp_new */
+    PyObject_GC_Del,                    /* tp_free */
+};
+
 /* module level code ********************************************************/
 
 PyDoc_STRVAR(module_doc,
@@ -4523,6 +4683,7 @@
         &_grouper_type,
         &tee_type,
         &teedataobject_type,
+        &chunks_type,
         NULL
     };
 
@@ -4542,3 +4703,6 @@
 
     return m;
 }
+
+
+