Add rsplit method for str and unicode builtin types.
SF feature request #801847.
Original patch is written by Sean Reifschneider.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index d3351df..9512059 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -1407,6 +1407,129 @@
return NULL;
}
+static PyObject *
+rsplit_whitespace(const char *s, int len, int maxsplit)
+{
+ int i, j, err;
+ PyObject* item;
+ PyObject *list = PyList_New(0);
+
+ if (list == NULL)
+ return NULL;
+
+ for (i = j = len - 1; i >= 0; ) {
+ while (i >= 0 && isspace(Py_CHARMASK(s[i])))
+ i--;
+ j = i;
+ while (i >= 0 && !isspace(Py_CHARMASK(s[i])))
+ i--;
+ if (j > i) {
+ if (maxsplit-- <= 0)
+ break;
+ item = PyString_FromStringAndSize(s+i+1, (int)(j-i));
+ if (item == NULL)
+ goto finally;
+ err = PyList_Insert(list, 0, item);
+ Py_DECREF(item);
+ if (err < 0)
+ goto finally;
+ while (i >= 0 && isspace(Py_CHARMASK(s[i])))
+ i--;
+ j = i;
+ }
+ }
+ if (j >= 0) {
+ item = PyString_FromStringAndSize(s, (int)(j + 1));
+ if (item == NULL)
+ goto finally;
+ err = PyList_Insert(list, 0, item);
+ Py_DECREF(item);
+ if (err < 0)
+ goto finally;
+ }
+ return list;
+ finally:
+ Py_DECREF(list);
+ return NULL;
+}
+
+
+PyDoc_STRVAR(rsplit__doc__,
+"S.rsplit([sep [,maxsplit]]) -> list of strings\n\
+\n\
+Return a list of the words in the string S, using sep as the\n\
+delimiter string, starting at the end of the string and working\n\
+to the front. If maxsplit is given, at most maxsplit splits are\n\
+done. If sep is not specified or is None, any whitespace string\n\
+is a separator.");
+
+static PyObject *
+string_rsplit(PyStringObject *self, PyObject *args)
+{
+ int len = PyString_GET_SIZE(self), n, i, j, err;
+ int maxsplit = -1;
+ const char *s = PyString_AS_STRING(self), *sub;
+ PyObject *list, *item, *subobj = Py_None;
+
+ if (!PyArg_ParseTuple(args, "|Oi:rsplit", &subobj, &maxsplit))
+ return NULL;
+ if (maxsplit < 0)
+ maxsplit = INT_MAX;
+ if (subobj == Py_None)
+ return rsplit_whitespace(s, len, maxsplit);
+ if (PyString_Check(subobj)) {
+ sub = PyString_AS_STRING(subobj);
+ n = PyString_GET_SIZE(subobj);
+ }
+#ifdef Py_USING_UNICODE
+ else if (PyUnicode_Check(subobj))
+ return PyUnicode_RSplit((PyObject *)self, subobj, maxsplit);
+#endif
+ else if (PyObject_AsCharBuffer(subobj, &sub, &n))
+ return NULL;
+ if (n == 0) {
+ PyErr_SetString(PyExc_ValueError, "empty separator");
+ return NULL;
+ }
+
+ list = PyList_New(0);
+ if (list == NULL)
+ return NULL;
+
+ j = len;
+ i = j - n;
+ while (i >= 0) {
+ if (s[i] == sub[0] && memcmp(s+i, sub, n) == 0) {
+ if (maxsplit-- <= 0)
+ break;
+ item = PyString_FromStringAndSize(s+i+n, (int)(j-i-n));
+ if (item == NULL)
+ goto fail;
+ err = PyList_Insert(list, 0, item);
+ Py_DECREF(item);
+ if (err < 0)
+ goto fail;
+ j = i;
+ i -= n;
+ }
+ else
+ i--;
+ }
+ item = PyString_FromStringAndSize(s, j);
+ if (item == NULL)
+ goto fail;
+ err = PyList_Insert(list, 0, item);
+ Py_DECREF(item);
+ if (err < 0)
+ goto fail;
+
+ return list;
+
+ fail:
+ Py_DECREF(list);
+ return NULL;
+}
+
PyDoc_STRVAR(join__doc__,
"S.join(sequence) -> string\n\
@@ -3064,6 +3187,7 @@
string.maketrans(). */
{"join", (PyCFunction)string_join, METH_O, join__doc__},
{"split", (PyCFunction)string_split, METH_VARARGS, split__doc__},
+ {"rsplit", (PyCFunction)string_rsplit, METH_VARARGS, rsplit__doc__},
{"lower", (PyCFunction)string_lower, METH_NOARGS, lower__doc__},
{"upper", (PyCFunction)string_upper, METH_NOARGS, upper__doc__},
{"islower", (PyCFunction)string_islower, METH_NOARGS, islower__doc__},