gh-46236: Document PyUnicode_RSplit, PyUnicode_Partition and PyUnicode_RPartition (#130191)

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Doc/c-api/unicode.rst

@@ -1398,6 +1398,20 @@ They all return ``NULL`` or ``-1`` if an exception occurs.
    separator.  At most *maxsplit* splits will be done.  If negative, no limit is
    set.  Separators are not included in the resulting list.
 
+   On error, return ``NULL`` with an exception set.
+
+   Equivalent to :py:meth:`str.split`.
+
+
+.. c:function:: PyObject* PyUnicode_RSplit(PyObject *unicode, PyObject *sep, Py_ssize_t maxsplit)
+
+   Similar to :c:func:`PyUnicode_Split`, but splitting will be done beginning
+   at the end of the string.
+
+   On error, return ``NULL`` with an exception set.
+
+   Equivalent to :py:meth:`str.rsplit`.
+
 
 .. c:function:: PyObject* PyUnicode_Splitlines(PyObject *unicode, int keepends)
 
@@ -1406,6 +1420,33 @@ They all return ``NULL`` or ``-1`` if an exception occurs.
    characters are not included in the resulting strings.
 
 
+.. c:function:: PyObject* PyUnicode_Partition(PyObject *unicode, PyObject *sep)
+
+   Split a Unicode string at the first occurrence of *sep*, and return
+   a 3-tuple containing the part before the separator, the separator itself,
+   and the part after the separator. If the separator is not found,
+   return a 3-tuple containing the string itself, followed by two empty strings.
+
+   *sep* must not be empty.
+
+   On error, return ``NULL`` with an exception set.
+
+   Equivalent to :py:meth:`str.partition`.
+
+
+.. c:function:: PyObject* PyUnicode_RPartition(PyObject *unicode, PyObject *sep)
+
+   Similar to :c:func:`PyUnicode_Partition`, but split a Unicode string at the
+   last occurrence of *sep*. If the separator is not found, return a 3-tuple
+   containing two empty strings, followed by the string itself.
+
+   *sep* must not be empty.
+
+   On error, return ``NULL`` with an exception set.
+
+   Equivalent to :py:meth:`str.rpartition`.
+
+
 .. c:function:: PyObject* PyUnicode_Join(PyObject *separator, PyObject *seq)
 
    Join a sequence of strings using the given *separator* and return the resulting

Doc/data/refcounts.dat

@@ -2655,13 +2655,26 @@ PyUnicode_Concat:PyObject*::+1:
 PyUnicode_Concat:PyObject*:left:0:
 PyUnicode_Concat:PyObject*:right:0:
 
+PyUnicode_Partition:PyObject*::+1:
+PyUnicode_Partition:PyObject*:unicode:0:
+PyUnicode_Partition:PyObject*:sep:0:
+
+PyUnicode_RPartition:PyObject*::+1:
+PyUnicode_RPartition:PyObject*:unicode:0:
+PyUnicode_RPartition:PyObject*:sep:0:
+
+PyUnicode_RSplit:PyObject*::+1:
+PyUnicode_RSplit:PyObject*:unicode:0:
+PyUnicode_RSplit:PyObject*:sep:0:
+PyUnicode_RSplit:Py_ssize_t:maxsplit::
+
 PyUnicode_Split:PyObject*::+1:
-PyUnicode_Split:PyObject*:left:0:
-PyUnicode_Split:PyObject*:right:0:
+PyUnicode_Split:PyObject*:unicode:0:
+PyUnicode_Split:PyObject*:sep:0:
 PyUnicode_Split:Py_ssize_t:maxsplit::
 
 PyUnicode_Splitlines:PyObject*::+1:
-PyUnicode_Splitlines:PyObject*:s:0:
+PyUnicode_Splitlines:PyObject*:unicode:0:
 PyUnicode_Splitlines:int:keepend::
 
 PyUnicode_Translate:PyObject*::+1:

Misc/NEWS.d/next/Documentation/2025-02-16-14-57-00.gh-issue-46236.2HuS4S.rst

@@ -0,0 +1,2 @@
+C API: Document :c:func:`PyUnicode_RSplit`, :c:func:`PyUnicode_Partition` and
+:c:func:`PyUnicode_RPartition`.