From: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Date: Mon, 30 Jun 2025 13:42:08 +0000 (+0100)
Subject: gh-48181: Document `codecs.charmap_build` (#135997)
X-Git-Tag: v3.15.0a1~1134
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2bdd50309f543f449d7d82b64ed6f60ae0aa80b9;p=thirdparty%2FPython%2Fcpython.git

gh-48181: Document `codecs.charmap_build` (#135997)
---

diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index 86511602fa5a..b231fa568cf3 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -53,6 +53,14 @@ any codec:
    :exc:`UnicodeDecodeError`). Refer to :ref:`codec-base-classes` for more
    information on codec error handling.
 
+.. function:: charmap_build(string)
+
+   Return a mapping suitable for encoding with a custom single-byte encoding.
+   Given a :class:`str` *string* of up to 256 characters representing a
+   decoding table, returns either a compact internal mapping object
+   ``EncodingMap`` or a :class:`dictionary <dict>` mapping character ordinals
+   to byte values. Raises a :exc:`TypeError` on invalid input.
+
 The full details for each codec can also be looked up directly:
 
 .. function:: lookup(encoding, /)