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author | Benjamin Peterson <benjamin@python.org> | 2009-10-04 14:49:41 (GMT) |
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committer | Benjamin Peterson <benjamin@python.org> | 2009-10-04 14:49:41 (GMT) |
commit | 4ac9ce4f9a33a330a555ae8015e2f2ae2780fafb (patch) | |
tree | b9bbcfd8f4aae362d8335d13e592f605b674ea19 /Doc/library/shelve.rst | |
parent | bd27aef8a0f776cc72387be31e1e74ecbcbbdf54 (diff) | |
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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
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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.
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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.
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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.
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r74782 | michael.foord | 2009-09-13 12:07:46 -0500 (Sun, 13 Sep 2009) | 1 line
Tutorial tweaks. Issue 6849.
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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.
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r74784 | georg.brandl | 2009-09-13 13:15:07 -0500 (Sun, 13 Sep 2009) | 1 line
Typo fix.
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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.
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r74786 | michael.foord | 2009-09-13 14:08:18 -0500 (Sun, 13 Sep 2009) | 1 line
Remove an extraneous space in unittest documentation.
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r74793 | georg.brandl | 2009-09-14 09:50:47 -0500 (Mon, 14 Sep 2009) | 1 line
#6908: fix association of hashlib hash attributes.
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r74795 | benjamin.peterson | 2009-09-14 22:36:26 -0500 (Mon, 14 Sep 2009) | 1 line
Py_SetPythonHome uses static storage #6913
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r74811 | georg.brandl | 2009-09-15 15:26:59 -0500 (Tue, 15 Sep 2009) | 1 line
Add Armin Ronacher.
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r74860 | benjamin.peterson | 2009-09-16 21:46:54 -0500 (Wed, 16 Sep 2009) | 1 line
kill bare except
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r74861 | benjamin.peterson | 2009-09-16 22:18:28 -0500 (Wed, 16 Sep 2009) | 1 line
pep 8 defaults
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r74863 | benjamin.peterson | 2009-09-16 22:27:33 -0500 (Wed, 16 Sep 2009) | 1 line
rationalize a bit
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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.
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r74886 | benjamin.peterson | 2009-09-17 16:33:46 -0500 (Thu, 17 Sep 2009) | 1 line
use macros
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r74896 | georg.brandl | 2009-09-18 02:22:41 -0500 (Fri, 18 Sep 2009) | 1 line
#6936: for interactive use, quit() is just fine.
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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.
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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.
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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.
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r74912 | georg.brandl | 2009-09-18 11:19:56 -0500 (Fri, 18 Sep 2009) | 1 line
Optimize optimization and fix method name in docstring.
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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.
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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.
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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.
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r74946 | georg.brandl | 2009-09-19 03:43:16 -0500 (Sat, 19 Sep 2009) | 1 line
Update bug tracker reference.
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r74952 | georg.brandl | 2009-09-19 05:42:34 -0500 (Sat, 19 Sep 2009) | 1 line
#6946: fix duplicate index entries for datetime classes.
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r74953 | georg.brandl | 2009-09-19 07:04:16 -0500 (Sat, 19 Sep 2009) | 1 line
Fix references to threading.enumerate().
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r74954 | georg.brandl | 2009-09-19 08:13:56 -0500 (Sat, 19 Sep 2009) | 1 line
Add Doug.
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r74955 | georg.brandl | 2009-09-19 08:20:49 -0500 (Sat, 19 Sep 2009) | 1 line
Add Mark Summerfield.
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r75015 | georg.brandl | 2009-09-22 05:55:08 -0500 (Tue, 22 Sep 2009) | 1 line
Fix encoding name.
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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.
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r75032 | benjamin.peterson | 2009-09-22 17:15:28 -0500 (Tue, 22 Sep 2009) | 1 line
fix typos/rephrase
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r75068 | benjamin.peterson | 2009-09-25 21:57:59 -0500 (Fri, 25 Sep 2009) | 1 line
comment out ugly xxx
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r75076 | vinay.sajip | 2009-09-26 09:53:32 -0500 (Sat, 26 Sep 2009) | 1 line
Tidied up name of parameter in StreamHandler
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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.
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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.
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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.
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r75129 | vinay.sajip | 2009-09-29 02:08:54 -0500 (Tue, 29 Sep 2009) | 1 line
Issue #7014: logging: Improved IronPython 2.6 compatibility.
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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.
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r75230 | benjamin.peterson | 2009-10-04 08:38:38 -0500 (Sun, 04 Oct 2009) | 1 line
test logging
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Diffstat (limited to 'Doc/library/shelve.rst')
-rw-r--r-- | Doc/library/shelve.rst | 45 |
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 |