diff options
| author | Matthew Schinckel <matt@schinckel.net> | 2019-03-30 23:59:03 +1030 |
|---|---|---|
| committer | Tim Graham <timograham@gmail.com> | 2019-03-30 09:29:03 -0400 |
| commit | c3c2ec54f59428cdf0a35abce594fd2ada35c209 (patch) | |
| tree | a2737ad3b6d272fa66e70ea9e809c526f0057704 /docs/ref/utils.txt | |
| parent | ad72895c60b4bc217fcd03108bed32587d561d0c (diff) | |
Refs #30278 -- Doc'd behavior of del on an unaccessed cached_property.
Thanks to Curtis Maloney for the description of the problem.
Diffstat (limited to 'docs/ref/utils.txt')
| -rw-r--r-- | docs/ref/utils.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/docs/ref/utils.txt b/docs/ref/utils.txt index 2becfea269..8316c916cd 100644 --- a/docs/ref/utils.txt +++ b/docs/ref/utils.txt @@ -473,6 +473,10 @@ https://web.archive.org/web/20110718035220/http://diveintomark.org/archives/2004 # set a value manually, that will persist on the instance until cleared person.friends = ["Huckleberry Finn", "Tom Sawyer"] + Because of the way the `descriptor protocol + <descriptor-invocation>`_ works, using ``del`` (or ``delattr``) on a + ``cached_property`` that hasn't been accessed raises ``AttributeError``. + As well as offering potential performance advantages, ``@cached_property`` can ensure that an attribute's value does not change unexpectedly over the life of an instance. This could occur with a method whose computation is |