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authorBenjamin Peterson <benjamin@python.org>2009-10-04 14:49:41 (GMT)
committerBenjamin Peterson <benjamin@python.org>2009-10-04 14:49:41 (GMT)
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Merged revisions 74779-74786,74793,74795,74811,74860-74861,74863,74876,74886,74896,74901,74903,74908,74912,74930,74933,74943,74946,74952-74955,75015,75019,75032,75068,75076,75095,75098,75102,75129,75139,75230 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk ........ r74779 | michael.foord | 2009-09-13 11:13:36 -0500 (Sun, 13 Sep 2009) | 1 line Change to tutorial wording for reading text / binary files on Windows. Issue #6301. ........ r74780 | michael.foord | 2009-09-13 11:40:02 -0500 (Sun, 13 Sep 2009) | 1 line Objects that compare equal automatically pass or fail assertAlmostEqual and assertNotAlmostEqual tests on unittest.TestCase. Issue 6567. ........ r74781 | michael.foord | 2009-09-13 11:46:19 -0500 (Sun, 13 Sep 2009) | 1 line Note that sys._getframe is not guaranteed to exist in all implementations of Python, and a corresponding note in inspect.currentframe. Issue 6712. ........ r74782 | michael.foord | 2009-09-13 12:07:46 -0500 (Sun, 13 Sep 2009) | 1 line Tutorial tweaks. Issue 6849. ........ r74783 | michael.foord | 2009-09-13 12:28:35 -0500 (Sun, 13 Sep 2009) | 1 line unittest.TestLoader.loadTestsFromName honors the loader suiteClass attribute. Issue 6866. ........ r74784 | georg.brandl | 2009-09-13 13:15:07 -0500 (Sun, 13 Sep 2009) | 1 line Typo fix. ........ r74785 | michael.foord | 2009-09-13 14:07:03 -0500 (Sun, 13 Sep 2009) | 1 line Test discovery in unittest will only attempt to import modules that are importable; i.e. their names are valid Python identifiers. If an import fails during discovery this will be recorded as an error and test discovery will continue. Issue 6568. ........ r74786 | michael.foord | 2009-09-13 14:08:18 -0500 (Sun, 13 Sep 2009) | 1 line Remove an extraneous space in unittest documentation. ........ r74793 | georg.brandl | 2009-09-14 09:50:47 -0500 (Mon, 14 Sep 2009) | 1 line #6908: fix association of hashlib hash attributes. ........ r74795 | benjamin.peterson | 2009-09-14 22:36:26 -0500 (Mon, 14 Sep 2009) | 1 line Py_SetPythonHome uses static storage #6913 ........ r74811 | georg.brandl | 2009-09-15 15:26:59 -0500 (Tue, 15 Sep 2009) | 1 line Add Armin Ronacher. ........ r74860 | benjamin.peterson | 2009-09-16 21:46:54 -0500 (Wed, 16 Sep 2009) | 1 line kill bare except ........ r74861 | benjamin.peterson | 2009-09-16 22:18:28 -0500 (Wed, 16 Sep 2009) | 1 line pep 8 defaults ........ r74863 | benjamin.peterson | 2009-09-16 22:27:33 -0500 (Wed, 16 Sep 2009) | 1 line rationalize a bit ........ r74876 | georg.brandl | 2009-09-17 11:15:53 -0500 (Thu, 17 Sep 2009) | 1 line #6932: remove paragraph that advises relying on __del__ being called. ........ r74886 | benjamin.peterson | 2009-09-17 16:33:46 -0500 (Thu, 17 Sep 2009) | 1 line use macros ........ r74896 | georg.brandl | 2009-09-18 02:22:41 -0500 (Fri, 18 Sep 2009) | 1 line #6936: for interactive use, quit() is just fine. ........ r74901 | georg.brandl | 2009-09-18 04:14:52 -0500 (Fri, 18 Sep 2009) | 1 line #6905: use better exception messages in inspect when the argument is of the wrong type. ........ r74903 | georg.brandl | 2009-09-18 04:18:27 -0500 (Fri, 18 Sep 2009) | 1 line #6938: "ident" is always a string, so use a format code which works. ........ r74908 | georg.brandl | 2009-09-18 08:57:11 -0500 (Fri, 18 Sep 2009) | 1 line Use str.format() to fix beginner's mistake with %-style string formatting. ........ r74912 | georg.brandl | 2009-09-18 11:19:56 -0500 (Fri, 18 Sep 2009) | 1 line Optimize optimization and fix method name in docstring. ........ r74930 | georg.brandl | 2009-09-18 16:21:41 -0500 (Fri, 18 Sep 2009) | 1 line #6925: rewrite docs for locals() and vars() a bit. ........ r74933 | georg.brandl | 2009-09-18 16:35:59 -0500 (Fri, 18 Sep 2009) | 1 line #6930: clarify description about byteorder handling in UTF decoder routines. ........ r74943 | georg.brandl | 2009-09-19 02:35:07 -0500 (Sat, 19 Sep 2009) | 1 line #6944: the argument to PyArg_ParseTuple should be a tuple, otherwise a SystemError is set. Also clean up another usage of PyArg_ParseTuple. ........ r74946 | georg.brandl | 2009-09-19 03:43:16 -0500 (Sat, 19 Sep 2009) | 1 line Update bug tracker reference. ........ r74952 | georg.brandl | 2009-09-19 05:42:34 -0500 (Sat, 19 Sep 2009) | 1 line #6946: fix duplicate index entries for datetime classes. ........ r74953 | georg.brandl | 2009-09-19 07:04:16 -0500 (Sat, 19 Sep 2009) | 1 line Fix references to threading.enumerate(). ........ r74954 | georg.brandl | 2009-09-19 08:13:56 -0500 (Sat, 19 Sep 2009) | 1 line Add Doug. ........ r74955 | georg.brandl | 2009-09-19 08:20:49 -0500 (Sat, 19 Sep 2009) | 1 line Add Mark Summerfield. ........ r75015 | georg.brandl | 2009-09-22 05:55:08 -0500 (Tue, 22 Sep 2009) | 1 line Fix encoding name. ........ r75019 | vinay.sajip | 2009-09-22 12:23:41 -0500 (Tue, 22 Sep 2009) | 1 line Fixed a typo, and added sections on optimization and using arbitrary objects as messages. ........ r75032 | benjamin.peterson | 2009-09-22 17:15:28 -0500 (Tue, 22 Sep 2009) | 1 line fix typos/rephrase ........ r75068 | benjamin.peterson | 2009-09-25 21:57:59 -0500 (Fri, 25 Sep 2009) | 1 line comment out ugly xxx ........ r75076 | vinay.sajip | 2009-09-26 09:53:32 -0500 (Sat, 26 Sep 2009) | 1 line Tidied up name of parameter in StreamHandler ........ r75095 | michael.foord | 2009-09-27 14:15:41 -0500 (Sun, 27 Sep 2009) | 1 line Test creation moved from TestProgram.parseArgs to TestProgram.createTests exclusively. Issue 6956. ........ r75098 | michael.foord | 2009-09-27 15:08:23 -0500 (Sun, 27 Sep 2009) | 1 line Documentation improvement for load_tests protocol in unittest. Issue 6515. ........ r75102 | skip.montanaro | 2009-09-27 21:12:27 -0500 (Sun, 27 Sep 2009) | 3 lines Patch from Thomas Barr so that csv.Sniffer will set doublequote property. Closes issue 6606. ........ r75129 | vinay.sajip | 2009-09-29 02:08:54 -0500 (Tue, 29 Sep 2009) | 1 line Issue #7014: logging: Improved IronPython 2.6 compatibility. ........ r75139 | raymond.hettinger | 2009-09-29 13:53:24 -0500 (Tue, 29 Sep 2009) | 3 lines Issue 7008: Better document str.title and show how to work around the apostrophe problem. ........ r75230 | benjamin.peterson | 2009-10-04 08:38:38 -0500 (Sun, 04 Oct 2009) | 1 line test logging ........
Diffstat (limited to 'Doc/library/shelve.rst')
-rw-r--r--Doc/library/shelve.rst45
1 files changed, 26 insertions, 19 deletions
diff --git a/Doc/library/shelve.rst b/Doc/library/shelve.rst
index 65303e9..7e4d7d9 100644
--- a/Doc/library/shelve.rst
+++ b/Doc/library/shelve.rst
@@ -27,27 +27,39 @@ lots of shared sub-objects. The keys are ordinary strings.
Because of Python semantics, a shelf cannot know when a mutable
persistent-dictionary entry is modified. By default modified objects are
- written only when assigned to the shelf (see :ref:`shelve-example`). If
- the optional *writeback* parameter is set to *True*, all entries accessed
- are cached in memory, and written back at close time; this can make it
- handier to mutate mutable entries in the persistent dictionary, but, if
- many entries are accessed, it can consume vast amounts of memory for the
- cache, and it can make the close operation very slow since all accessed
- entries are written back (there is no way to determine which accessed
- entries are mutable, nor which ones were actually mutated).
+ written only when assigned to the shelf (see :ref:`shelve-example`). If the
+ optional *writeback* parameter is set to *True*, all entries accessed are
+ cached in memory, and written back on :meth:`sync` and :meth:`close`; this
+ can make it handier to mutate mutable entries in the persistent dictionary,
+ but, if many entries are accessed, it can consume vast amounts of memory for
+ the cache, and it can make the close operation very slow since all accessed
+ entries are written back (there is no way to determine which accessed entries
+ are mutable, nor which ones were actually mutated).
+
+ .. note::
+
+ Do not rely on the shelf being closed automatically; always call
+ :meth:`close` explicitly when you don't need it any more, or use a
+ :keyword:`with` statement with :func:`contextlib.closing`.
+
Shelf objects support all methods supported by dictionaries. This eases the
transition from dictionary based scripts to those requiring persistent storage.
-One additional method is supported:
-
+Two additional methods are supported:
.. method:: Shelf.sync()
- Write back all entries in the cache if the shelf was opened with *writeback* set
- to *True*. Also empty the cache and synchronize the persistent dictionary on
- disk, if feasible. This is called automatically when the shelf is closed with
- :meth:`close`.
+ Write back all entries in the cache if the shelf was opened with *writeback*
+ set to :const:`True`. Also empty the cache and synchronize the persistent
+ dictionary on disk, if feasible. This is called automatically when the shelf
+ is closed with :meth:`close`.
+
+.. method:: Shelf.close()
+
+ Synchronize and close the persistent *dict* object. Operations on a closed
+ shelf will fail with a :exc:`ValueError`.
+
.. seealso::
@@ -71,11 +83,6 @@ Restrictions
database should be fairly small, and in rare cases key collisions may cause
the database to refuse updates.
-* Depending on the implementation, closing a persistent dictionary may or may
- not be necessary to flush changes to disk. The :meth:`__del__` method of the
- :class:`Shelf` class calls the :meth:`close` method, so the programmer generally
- need not do this explicitly.
-
* The :mod:`shelve` module does not support *concurrent* read/write access to
shelved objects. (Multiple simultaneous read accesses are safe.) When a
program has a shelf open for writing, no other program should have it open for