[Python-checkins] peps: pep-0492: Rewrite "Why not a __future__ import" section; tx to Nick Coghlan.

[yury.selivanov]

https://hg.python.org/peps/rev/5db3ad3d540b
changeset:   5812:5db3ad3d540b
user:        Yury Selivanov <yselivanov at sprymix.com>
date:        Wed Apr 29 23:18:03 2015 -0400
summary:
  pep-0492: Rewrite "Why not a __future__ import" section; tx to Nick Coghlan.

files:
  pep-0492.txt |  13 +++++--------
  1 files changed, 5 insertions(+), 8 deletions(-)


diff --git a/pep-0492.txt b/pep-0492.txt
--- a/pep-0492.txt
+++ b/pep-0492.txt
@@ -1108,14 +1108,11 @@
 Why not a __future__ import
 ---------------------------
 
-``__future__`` imports are inconvenient and easy to forget to add.
-Also, they are enabled for the whole source file.  Consider that there
-is a big project with a popular module named "async.py".  With future
-imports it is required to either import it using ``__import__()`` or
-``importlib.import_module()`` calls, or to rename the module.  The
-proposed approach makes it possible to continue using old code and
-modules without a hassle, while coming up with a migration plan for
-future python versions.
+`Transition Plan`_ section explains how tokenizer is modified to treat
+``async`` and ``await`` as keywords *only* in ``async def`` blocks.
+Hence ``async def`` fills the role that a module level compiler
+declaration like ``from __future__ import async_await`` would otherwise
+fill.
 
 
 Why magic methods start with "a"

-- 
Repository URL: https://hg.python.org/peps