From b5f41515a5cd421f574edd6e5edff6cd89a809b1 Mon Sep 17 00:00:00 2001 From: Nick Coghlan Date: Sun, 18 Jun 2017 12:01:45 +1000 Subject: [PATCH] PEP 538: Note significant implementation-driven changes --- pep-0538.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/pep-0538.txt b/pep-0538.txt index b9a388b4d..ebe967db7 100644 --- a/pep-0538.txt +++ b/pep-0538.txt @@ -83,6 +83,21 @@ opt in to this locale coercion behaviour for the Python 3.6.x series by applying the necessary changes as a downstream patch. +Implementation Notes +==================== + +Attempting to implement the PEP as originally accepted showed that the +proposal to emit locale coercion and compatibility warnings by default +simply wasn't practical (there were too many cases where previously working +code failed *because of the warnings*, rather than because of latent locale +handling defects in the affected code). + +As a result, the ``PY_WARN_ON_C_LOCALE`` config flag was removed, and replaced +with a runtime ``PYTHONCOERCECLOCALE=warn`` environment variable setting +that allows developers and system integrators to opt-in to receiving locale +coercion and compatibility warnings, without emitting them by default. + + Background ==========