[Python-checkins] bpo-33836: Recommend keyword-only param for memoization in FAQ (GH-7687)

[Mariatta]

https://github.com/python/cpython/commit/2707e41a5c7ede30349cc7dbd66f8be564965d7c
commit: 2707e41a5c7ede30349cc7dbd66f8be564965d7c
branch: master
author: Noah Haasis <haasis_noah at yahoo.de>
committer: Mariatta <Mariatta at users.noreply.github.com>
date: 2018-06-15T20:29:11-07:00
summary:

bpo-33836: Recommend keyword-only param for memoization in FAQ (GH-7687)

Update the the signature in the code example to make `_cache` a keyword-only parameter.

files:
M Doc/faq/programming.rst

diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst
index d986ab642bfb..53f3b7f528c0 100644
--- a/Doc/faq/programming.rst
+++ b/Doc/faq/programming.rst
@@ -371,8 +371,8 @@ compute, a common technique is to cache the parameters and the resulting value
 of each call to the function, and return the cached value if the same value is
 requested again.  This is called "memoizing", and can be implemented like this::
 
-   # Callers will never provide a third parameter for this function.
-   def expensive(arg1, arg2, _cache={}):
+   # Callers can only provide two parameters and optionally pass _cache by keyword
+   def expensive(arg1, arg2, *, _cache={}):
        if (arg1, arg2) in _cache:
            return _cache[(arg1, arg2)]