From: Georg Brandl Date: Sun, 14 Feb 2010 13:40:45 +0000 (+0000) Subject: Merged revisions 78182,78188 via svnmerge from X-Git-Tag: v2.6.5rc1~70 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2fe3b3d4beefa1818e4f16901b839cd05304bdca;p=python Merged revisions 78182,78188 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r78182 | georg.brandl | 2010-02-14 09:18:23 +0100 (So, 14 Feb 2010) | 1 line #7926: fix stray parens. ........ r78188 | georg.brandl | 2010-02-14 14:38:12 +0100 (So, 14 Feb 2010) | 1 line #7926: fix-up wording. ........ --- diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst index ea67ba167b..c6f7c2da47 100644 --- a/Doc/whatsnew/2.6.rst +++ b/Doc/whatsnew/2.6.rst @@ -346,9 +346,10 @@ A high-level explanation of the context management protocol is: * The code in *BLOCK* is executed. -* If *BLOCK* raises an exception, the :meth:`__exit__(type, value, traceback)` - is called with the exception details, the same values returned by - :func:`sys.exc_info`. The method's return value controls whether the exception +* If *BLOCK* raises an exception, the context manager's :meth:`__exit__` method + is called with three arguments, the exception details (``type, value, traceback``, + the same values returned by :func:`sys.exc_info`, which can also be ``None`` + if no exception occurred). The method's return value controls whether an exception is re-raised: any false value re-raises the exception, and ``True`` will result in suppressing it. You'll only rarely want to suppress the exception, because if you do the author of the code containing the ':keyword:`with`' statement will @@ -459,7 +460,7 @@ could be written as:: with db_transaction(db) as cursor: ... -The :mod:`contextlib` module also has a :func:`nested(mgr1, mgr2, ...)` function +The :mod:`contextlib` module also has a ``nested(mgr1, mgr2, ...)`` function that combines a number of context managers so you don't need to write nested ':keyword:`with`' statements. In this example, the single ':keyword:`with`' statement both starts a database transaction and acquires a thread lock:: @@ -468,8 +469,9 @@ statement both starts a database transaction and acquires a thread lock:: with nested (db_transaction(db), lock) as (cursor, locked): ... -Finally, the :func:`closing(object)` function returns *object* so that it can be -bound to a variable, and calls ``object.close`` at the end of the block. :: +Finally, the :func:`closing` function returns its argument so that it can be +bound to a variable, and calls the argument's ``.close()`` method at the end +of the block. :: import urllib, sys from contextlib import closing