[Python-checkins] Doc: Add missing entry for functools.cached_property (GH-16803)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/380d443a6ac73cb4719d86fd5781544630bcec5e
commit: 380d443a6ac73cb4719d86fd5781544630bcec5e
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2019-10-18T00:21:05-07:00
summary:

Doc: Add missing entry for functools.cached_property (GH-16803)

(cherry picked from commit 93b81e1fcbeb61c1b49ac2fa52c5a0dff929940b)

Co-authored-by: Stéphane Wirtel <stephane at wirtel.be>

files:
M Doc/whatsnew/3.8.rst

diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst
index e1388e2169f47..ef4209f9db499 100644
--- a/Doc/whatsnew/3.8.rst
+++ b/Doc/whatsnew/3.8.rst
@@ -685,6 +685,22 @@ than as a function returning a decorator.  So both of these are now supported::
 
 (Contributed by Raymond Hettinger in :issue:`36772`.)
 
+Added a new :func:`functools.cached_property` decorator, for computed properties
+cached for the life of the instance. ::
+
+   import functools
+   import statistics
+
+   class Dataset:
+      def __init__(self, sequence_of_numbers):
+         self.data = sequence_of_numbers
+
+      @functools.cached_property
+      def variance(self):
+         return statistics.variance(self.data)
+
+(Contributed by Carl Meyer in :issue:`21145`)
+
 
 gc
 --