Renamed _length_cue() to __length_hint__(). See:

http://mail.python.org/pipermail/python-dev/2006-February/060524.html

diff --git a/Include/abstract.h b/Include/abstract.h
index 7e0bc4d6ad6eefb2cc03b0736531ad1a2316fab3..fd151735cea6b898df615fe921cfa44cf18baadc 100644 (file)
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -422,20 +422,25 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
      PyAPI_FUNC(int) PyObject_Length(PyObject *o);
 #define PyObject_Length PyObject_Size
 
-     PyAPI_FUNC(int) _PyObject_LengthCue(PyObject *o);
+     PyAPI_FUNC(int) _PyObject_LengthHint(PyObject *o);
 
        /*
          Return the size of object o.  If the object, o, provides
         both sequence and mapping protocols, the sequence size is
         returned. On error, -1 is returned.  If the object provides
-        a _length_cue() method, its value is returned.  This is the 
+        a __length_hint__() method, its value is returned.  This is an
+        internal undocumented API provided for performance reasons;
+        for compatibility, don't use it outside the core.  This is the
         equivalent to the Python expression: 
                try:
                        return len(o)
                except (AttributeError, TypeError):
-                       if hasattr(o, '_length_cue'):
-                               return o._length_cue()
-                       raise
+                       exc_type, exc_value, exc_tb = sys.exc_info()
+                       try:
+                               return o.__length_hint__()
+                       except:
+                               pass
+                       raise exc_type, exc_value, exc_tb
        */
 
      PyAPI_FUNC(PyObject *) PyObject_GetItem(PyObject *o, PyObject *key);

diff --git a/Lib/test/test_iterlen.py b/Lib/test/test_iterlen.py
index 1770de2c0ad383650c1d71eac200a1faec959781..bcd0a6f4c2a79cc69fff9b32d968bb3262b83614 100644 (file)
--- a/Lib/test/test_iterlen.py
+++ b/Lib/test/test_iterlen.py
@@ -55,7 +55,9 @@ def len(obj):
         return _len(obj)
     except TypeError:
         try:
-            return obj._length_cue()
+            # note: this is an internal undocumented API,
+            # don't rely on it in your own programs
+            return obj.__length_hint__()
         except AttributeError:
             raise TypeError
 

diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index e26065c51a0a97d1fade2e38503dbe482a47e08c..6ff12154aa0b47ff1e9fc9cab8c3983acd610dfb 100644 (file)
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -607,7 +607,9 @@ class TestBasicOps(unittest.TestCase):
         for v in self.set:
             self.assert_(v in self.values)
         setiter = iter(self.set)
-        self.assertEqual(setiter._length_cue(), len(self.set))
+        # note: __length_hint__ is an internal undocumented API,
+        # don't rely on it in your own programs
+        self.assertEqual(setiter.__length_hint__(), len(self.set))
 
     def test_pickling(self):
         p = pickle.dumps(self.set)

diff --git a/Modules/collectionsmodule.c b/Modules/collectionsmodule.c
index 16f25dfaae00ccdb5e974ee8ada43633087b73fc..20031549ee4ae412ffed93de6750cdddbc1db9d0 100644 (file)
--- a/Modules/collectionsmodule.c
+++ b/Modules/collectionsmodule.c
@@ -941,10 +941,10 @@ dequeiter_len(dequeiterobject *it)
        return PyInt_FromLong(it->counter);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef dequeiter_methods[] = {
-       {"_length_cue", (PyCFunction)dequeiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)dequeiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index a7ecf93e9b23be1f8a4bac597c2e6f1ec6bbc7f5..4b8ed696caec45f9479277c5af625a6a725a0437 100644 (file)
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -2346,10 +2346,10 @@ repeat_len(repeatobject *ro)
         return PyInt_FromLong(ro->cnt);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef repeat_methods[] = {
-       {"_length_cue", (PyCFunction)repeat_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)repeat_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/abstract.c b/Objects/abstract.c
index 8a5166ebf87e60ee16ed37314e0ee0dc3b355494..b794974b021238a5dea0f40424f331869760e2c5 100644 (file)
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -82,7 +82,7 @@ PyObject_Length(PyObject *o)
 #define PyObject_Length PyObject_Size
 
 int
-_PyObject_LengthCue(PyObject *o)
+_PyObject_LengthHint(PyObject *o)
 {
        int rv = PyObject_Size(o);
        if (rv != -1)
@@ -92,7 +92,7 @@ _PyObject_LengthCue(PyObject *o)
                PyObject *err_type, *err_value, *err_tb, *ro;
 
                PyErr_Fetch(&err_type, &err_value, &err_tb);
-               ro = PyObject_CallMethod(o, "_length_cue", NULL);
+               ro = PyObject_CallMethod(o, "__length_hint__", NULL);
                if (ro != NULL) {
                        rv = (int)PyInt_AsLong(ro);
                        Py_DECREF(ro);
@@ -1463,7 +1463,7 @@ PySequence_Tuple(PyObject *v)
                return NULL;
 
        /* Guess result size and allocate space. */
-       n = _PyObject_LengthCue(v);
+       n = _PyObject_LengthHint(v);
        if (n < 0) {
                if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
                    !PyErr_ExceptionMatches(PyExc_AttributeError)) {

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index cf88f340ea4f840433471fe2450997ca1fe4e4d3..1deb26cc4d612d6be23e5b128cd3ee5d81ad4bcb 100644 (file)
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2063,10 +2063,10 @@ dictiter_len(dictiterobject *di)
        return PyInt_FromLong(len);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef dictiter_methods[] = {
-       {"_length_cue", (PyCFunction)dictiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)dictiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/enumobject.c b/Objects/enumobject.c
index 8c3eab1692f01f23ce33fc6d038940e73296609f..7a5d1a162a8b64e308942bbe21cf4472c450d2ce 100644 (file)
--- a/Objects/enumobject.c
+++ b/Objects/enumobject.c
@@ -252,10 +252,10 @@ reversed_len(reversedobject *ro)
        return PyInt_FromLong((seqsize < position)  ?  0  :  position);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef reversediter_methods[] = {
-       {"_length_cue", (PyCFunction)reversed_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)reversed_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/iterobject.c b/Objects/iterobject.c
index fdee3ca9178efa0fc199520cc34eb31134d58c84..90dc3f0e3ad07055677fc912fdfd3a532c43a442 100644 (file)
--- a/Objects/iterobject.c
+++ b/Objects/iterobject.c
@@ -87,10 +87,10 @@ iter_len(seqiterobject *it)
        return PyInt_FromLong(0);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef seqiter_methods[] = {
-       {"_length_cue", (PyCFunction)iter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)iter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 04671f4219643c523ef0af6e73b1bc760910d3ac..8ba317a0e12f020f856852b5c4b8d0fbf4a729c9 100644 (file)
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -775,7 +775,7 @@ listextend(PyListObject *self, PyObject *b)
        iternext = *it->ob_type->tp_iternext;
 
        /* Guess a result list size. */
-       n = _PyObject_LengthCue(b);
+       n = _PyObject_LengthHint(b);
        if (n < 0) {
                if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
                    !PyErr_ExceptionMatches(PyExc_AttributeError)) {
@@ -2776,10 +2776,10 @@ listiter_len(listiterobject *it)
        return PyInt_FromLong(0);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef listiter_methods[] = {
-       {"_length_cue", (PyCFunction)listiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)listiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index 3cc5504631bfafa41ba5fd74c223ac1184c115a0..cfd9100d4d6f79949189940af0e0e0ef36031bd8 100644 (file)
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -268,10 +268,10 @@ rangeiter_len(rangeiterobject *r)
        return PyInt_FromLong(r->len - r->index);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef rangeiter_methods[] = {
-       {"_length_cue", (PyCFunction)rangeiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)rangeiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/setobject.c b/Objects/setobject.c
index 2494baeab8f85479c602202036eeb97c492e9173..baa2d01f418163aa7c4a170788e8660a6ee87eb7 100644 (file)
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -758,10 +758,10 @@ setiter_len(setiterobject *si)
        return PyInt_FromLong(len);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef setiter_methods[] = {
-       {"_length_cue", (PyCFunction)setiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)setiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 3fd311a483db5321d1af95601afce7d76dec8a32..8ea29f03a96455821eeaafd61b4ba36e86681403 100644 (file)
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -860,10 +860,10 @@ tupleiter_len(tupleiterobject *it)
        return PyInt_FromLong(len);
 }
 
-PyDoc_STRVAR(length_cue_doc, "Private method returning an estimate of len(list(it)).");
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
 
 static PyMethodDef tupleiter_methods[] = {
-       {"_length_cue", (PyCFunction)tupleiter_len, METH_NOARGS, length_cue_doc},
+       {"__length_hint__", (PyCFunction)tupleiter_len, METH_NOARGS, length_hint_doc},
        {NULL,          NULL}           /* sentinel */
 };
 

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index f8d23ad4cc9091a2388f8e18b44c13d5fefe83eb..362294f038a5ba2be013801199466906acd89382 100644 (file)
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -220,7 +220,7 @@ builtin_filter(PyObject *self, PyObject *args)
                goto Fail_arg;
 
        /* Guess a result list size. */
-       len = _PyObject_LengthCue(seq);
+       len = _PyObject_LengthHint(seq);
        if (len < 0) {
                if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
                    !PyErr_ExceptionMatches(PyExc_AttributeError)) {
@@ -875,7 +875,7 @@ builtin_map(PyObject *self, PyObject *args)
                }
 
                /* Update len. */
-               curlen = _PyObject_LengthCue(curseq);
+               curlen = _PyObject_LengthHint(curseq);
                if (curlen < 0) {
                        if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
                            !PyErr_ExceptionMatches(PyExc_AttributeError)) {
@@ -2111,7 +2111,7 @@ builtin_zip(PyObject *self, PyObject *args)
        len = -1;       /* unknown */
        for (i = 0; i < itemsize; ++i) {
                PyObject *item = PyTuple_GET_ITEM(args, i);
-               int thislen = _PyObject_LengthCue(item);
+               int thislen = _PyObject_LengthHint(item);
                if (thislen < 0) {
                        if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
                            !PyErr_ExceptionMatches(PyExc_AttributeError)) {