From d7c7adde003ddca5cbe4fc47cf09464ab95a066e Mon Sep 17 00:00:00 2001
From: Zac Hatfield-Dodds <Zac-HD@users.noreply.github.com>
Date: Sun, 12 Jan 2020 19:04:14 +1000
Subject: [PATCH] bpo-12159: Document sys.maxsize limit in len() function
 reference (GH-17934)

---
 Doc/library/functions.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index dc3391ffe88..cc48597ef91 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -892,6 +892,11 @@ are always available.  They are listed here in alphabetical order.
    sequence (such as a string, bytes, tuple, list, or range) or a collection
    (such as a dictionary, set, or frozen set).
 
+   .. impl-detail::
+
+      ``len`` raises :exc:`OverflowError` on lengths larger than
+      :data:`sys.maxsize`, such as :class:`range(2 ** 100) <range>`.
+
 
 .. _func-list:
 .. class:: list([iterable])