[Python-checkins] [docs] Mention how to get/set a bigint PyLong via the C API (#101270)

[gpshead]

https://github.com/python/cpython/commit/e244401ce508ad391295beb636e499fcc6797a2a
commit: e244401ce508ad391295beb636e499fcc6797a2a
branch: main
author: Gregory P. Smith <greg at krypto.org>
committer: gpshead <greg at krypto.org>
date: 2023-01-23T21:20:53-08:00
summary:

[docs] Mention how to get/set a bigint PyLong via the C API (#101270)

We don't need direct C APIs to get at a bigint representation of PyLong but we
do want the few people who need to understand how.

Additional Author:  CAM-Gerlach

files:
M Doc/c-api/long.rst

diff --git a/Doc/c-api/long.rst b/Doc/c-api/long.rst
index 4f6f865db8be..41b5632d2300 100644
--- a/Doc/c-api/long.rst
+++ b/Doc/c-api/long.rst
@@ -94,6 +94,10 @@ distinguished from a number.  Use :c:func:`PyErr_Occurred` to disambiguate.
    ignored.  If there are no digits or *str* is not NULL-terminated following the
    digits and trailing whitespace, :exc:`ValueError` will be raised.
 
+   .. seealso:: Python methods :meth:`int.to_bytes` and :meth:`int.from_bytes`
+      to convert a :c:type:`PyLongObject` to/from an array of bytes in base
+      ``256``. You can call those from C using :c:func:`PyObject_CallMethod`.
+
 
 .. c:function:: PyObject* PyLong_FromUnicodeObject(PyObject *u, int base)