The doccumentation at https://docs.python.org/3.10/library/weakref.html cautions that the `WeakKeyDictionary` and `WeakValueDictionary` are susceptible to the problem of dictionary mutation during iteration.
These notes present the user with a problem that has no easy solution.
I dug into the implementation and found that fortunately, Antoine Pitrou already addressed this challenge (10 years ago!) by introducing an `_IterationGuard` context manager to the implementation, which delays mutation while an iteration is in progress.
I asked for confirmation and @pitrou agreed that these notes could be removed:
c1baa601e2 (commitcomment-39514438)
Reflecting changes to the code, removed weakref.ReferenceError from weakref.rst and exceptions.rst.
Issue submitter provided evidence that the `weakref.ReferenceError` alias for `ReferenceError` was removed from the code in 2007. Working with @gvanrossum at PyCascades CPython sprint we looked at the code and confirmed that `weakref.ReferenceError` was no longer in `weakref.py`.
Based on that analysis I removed references `weakref.ReferenceError` from the two documents where it was still being referenced: `weakref.rst` and `exceptions.rst`.
https://bugs.python.org/issue38374
Also add a missing word to gc entry, and delete a now-obsolete doc note
in the weakref __callback__ docs. (Opened an issue for rewriting
the section that compares finalizers and __del__ method.)
weakref callbacks.
This is 2e446e87ac5b except that collections/__init__.py has been
modified to import proxy from _weakref instead of weakref. This
eliminates an import cycle which seems to cause a problem on Unix but
not Windows.
svn+ssh://pythondev@svn.python.org/python/trunk
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r79060 | collin.winter | 2010-03-18 14:54:01 -0700 (Thu, 18 Mar 2010) | 4 lines
Add support for weak references to code objects. This will be used by an optimization in the incoming Python 3 JIT.
Patch by Reid Kleckner!
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svn+ssh://pythondev@svn.python.org/python/trunk
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r75149 | gregory.p.smith | 2009-09-29 16:56:31 -0500 (Tue, 29 Sep 2009) | 3 lines
Mention issue6972 in extractall docs about overwriting things outside of
the supplied path.
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r75260 | andrew.kuchling | 2009-10-05 16:24:20 -0500 (Mon, 05 Oct 2009) | 1 line
Wording fix
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r75261 | andrew.kuchling | 2009-10-05 16:24:35 -0500 (Mon, 05 Oct 2009) | 1 line
Fix narkup
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r75262 | andrew.kuchling | 2009-10-05 16:25:03 -0500 (Mon, 05 Oct 2009) | 1 line
Document 'skip' parameter to constructor
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r75263 | andrew.kuchling | 2009-10-05 16:25:35 -0500 (Mon, 05 Oct 2009) | 1 line
Note side benefit of socket.create_connection()
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r75265 | andrew.kuchling | 2009-10-05 17:31:11 -0500 (Mon, 05 Oct 2009) | 1 line
Reword sentence
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r75266 | andrew.kuchling | 2009-10-05 17:32:48 -0500 (Mon, 05 Oct 2009) | 1 line
Use standard comma punctuation; reword some sentences in the docs
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r75267 | andrew.kuchling | 2009-10-05 17:42:56 -0500 (Mon, 05 Oct 2009) | 1 line
Backport r73983: Document the thousands separator.
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r75292 | benjamin.peterson | 2009-10-08 22:11:36 -0500 (Thu, 08 Oct 2009) | 1 line
death to old CVS keyword
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r75300 | benjamin.peterson | 2009-10-09 16:48:14 -0500 (Fri, 09 Oct 2009) | 1 line
fix some coding style
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r75376 | benjamin.peterson | 2009-10-11 20:26:07 -0500 (Sun, 11 Oct 2009) | 1 line
platform we don't care about
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r75405 | neil.schemenauer | 2009-10-14 12:17:14 -0500 (Wed, 14 Oct 2009) | 4 lines
Issue #1754094: Improve the stack depth calculation in the compiler.
There should be no other effect than a small decrease in memory use.
Patch by Christopher Tur Lesniewski-Laas.
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r75429 | benjamin.peterson | 2009-10-14 20:47:28 -0500 (Wed, 14 Oct 2009) | 1 line
pep8ify if blocks
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r75430 | benjamin.peterson | 2009-10-14 20:49:37 -0500 (Wed, 14 Oct 2009) | 1 line
use floor division and add a test that exercises the tabsize codepath
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r75431 | benjamin.peterson | 2009-10-14 20:56:25 -0500 (Wed, 14 Oct 2009) | 1 line
change test to what I intended
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r75432 | benjamin.peterson | 2009-10-14 22:05:39 -0500 (Wed, 14 Oct 2009) | 1 line
some cleanups
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r75433 | benjamin.peterson | 2009-10-14 22:06:55 -0500 (Wed, 14 Oct 2009) | 1 line
make inspect.isabstract() always return a boolean; add a test for it, too #7069
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r75437 | benjamin.peterson | 2009-10-15 10:44:46 -0500 (Thu, 15 Oct 2009) | 1 line
only clear a module's __dict__ if the module is the only one with a reference to it #7140
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r75445 | vinay.sajip | 2009-10-16 09:06:44 -0500 (Fri, 16 Oct 2009) | 1 line
Issue #7120: logging: Removed import of multiprocessing which is causing crash in GAE.
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r75501 | antoine.pitrou | 2009-10-18 13:37:11 -0500 (Sun, 18 Oct 2009) | 3 lines
Add a comment about unreachable code, and fix a typo
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r75551 | benjamin.peterson | 2009-10-19 22:14:10 -0500 (Mon, 19 Oct 2009) | 1 line
use property api
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r75572 | benjamin.peterson | 2009-10-20 16:55:17 -0500 (Tue, 20 Oct 2009) | 1 line
clarify buffer arg #7178
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r75589 | benjamin.peterson | 2009-10-21 21:26:47 -0500 (Wed, 21 Oct 2009) | 1 line
whitespace
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r75590 | benjamin.peterson | 2009-10-21 21:36:47 -0500 (Wed, 21 Oct 2009) | 1 line
rewrite to be nice to other implementations
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r75591 | benjamin.peterson | 2009-10-21 21:50:38 -0500 (Wed, 21 Oct 2009) | 4 lines
rewrite for style, clarify, and comments
Also, use the hasattr() like scheme of allowing BaseException exceptions through.
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r75657 | antoine.pitrou | 2009-10-24 07:41:27 -0500 (Sat, 24 Oct 2009) | 3 lines
Fix compilation error in debug mode.
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r75742 | benjamin.peterson | 2009-10-26 17:51:16 -0500 (Mon, 26 Oct 2009) | 1 line
use 'is' instead of id()
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r75868 | benjamin.peterson | 2009-10-27 15:59:18 -0500 (Tue, 27 Oct 2009) | 1 line
test expect base classes
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r75952 | georg.brandl | 2009-10-29 15:38:32 -0500 (Thu, 29 Oct 2009) | 1 line
Use the correct function name in docstring.
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r75953 | georg.brandl | 2009-10-29 15:39:50 -0500 (Thu, 29 Oct 2009) | 1 line
Remove mention of the old -X command line switch.
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r75954 | georg.brandl | 2009-10-29 15:53:00 -0500 (Thu, 29 Oct 2009) | 1 line
Use constants instead of magic integers for test result. Do not re-run with --verbose3 for environment changing tests.
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r75955 | georg.brandl | 2009-10-29 15:54:03 -0500 (Thu, 29 Oct 2009) | 1 line
Use a single style for all the docstrings in the math module.
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r75956 | georg.brandl | 2009-10-29 16:16:34 -0500 (Thu, 29 Oct 2009) | 1 line
I do not think the "railroad" program mentioned is still available.
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r75957 | georg.brandl | 2009-10-29 16:44:56 -0500 (Thu, 29 Oct 2009) | 1 line
Fix constant name.
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r76057 | benjamin.peterson | 2009-11-02 09:06:45 -0600 (Mon, 02 Nov 2009) | 1 line
prevent a rather unlikely segfault
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r76105 | georg.brandl | 2009-11-04 01:38:12 -0600 (Wed, 04 Nov 2009) | 1 line
#7259: show correct equivalent for operator.i* operations in docstring; fix minor issues in operator docs.
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r76139 | benjamin.peterson | 2009-11-06 19:04:38 -0600 (Fri, 06 Nov 2009) | 1 line
spelling
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r76143 | georg.brandl | 2009-11-07 02:26:07 -0600 (Sat, 07 Nov 2009) | 1 line
#7271: fix typo.
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r76162 | benjamin.peterson | 2009-11-08 22:10:53 -0600 (Sun, 08 Nov 2009) | 1 line
discuss how to use -p
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r76223 | georg.brandl | 2009-11-12 02:29:46 -0600 (Thu, 12 Nov 2009) | 1 line
Give the profile module a module directive.
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svn+ssh://pythondev@svn.python.org/python/trunk
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r74524 | gregory.p.smith | 2009-08-20 04:39:38 -0500 (Thu, 20 Aug 2009) | 2 lines
Add weakref support to the thread.lock type.
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r74556 | kristjan.jonsson | 2009-08-27 17:20:21 -0500 (Thu, 27 Aug 2009) | 2 lines
issue 6275
Add an "exc_value" attribute to the _AssertRaisesContext context manager in the unittest package. This allows further tests on the exception that was raised after the context manager exits.
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svn+ssh://pythondev@svn.python.org/python/trunk
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r61724 | martin.v.loewis | 2008-03-22 01:01:12 +0100 (Sat, 22 Mar 2008) | 49 lines
Merged revisions 61602-61723 via svnmerge from
svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3
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r61626 | david.wolever | 2008-03-19 17:19:16 +0100 (Mi, 19 M?\195?\164r 2008) | 1 line
Added fixer for implicit local imports. See #2414.
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r61628 | david.wolever | 2008-03-19 17:57:43 +0100 (Mi, 19 M?\195?\164r 2008) | 1 line
Added a class for tests which should not run if a particular import is found.
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r61629 | collin.winter | 2008-03-19 17:58:19 +0100 (Mi, 19 M?\195?\164r 2008) | 1 line
Two more relative import fixes in pgen2.
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r61635 | david.wolever | 2008-03-19 20:16:03 +0100 (Mi, 19 M?\195?\164r 2008) | 1 line
Fixed print fixer so it will do the Right Thing when it encounters __future__.print_function. 2to3 gets upset, though, so the tests have been commented out.
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r61637 | david.wolever | 2008-03-19 21:37:17 +0100 (Mi, 19 M?\195?\164r 2008) | 3 lines
Added a fixer for itertools imports (from itertools import imap, ifilterfalse --> from itertools import filterfalse)
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r61645 | david.wolever | 2008-03-19 23:22:35 +0100 (Mi, 19 M?\195?\164r 2008) | 1 line
SVN is happier when you add the files you create... -_-'
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r61654 | david.wolever | 2008-03-20 01:09:56 +0100 (Do, 20 M?\195?\164r 2008) | 1 line
Added an explicit sort order to fixers -- fixes problems like #2427
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r61664 | david.wolever | 2008-03-20 04:32:40 +0100 (Do, 20 M?\195?\164r 2008) | 3 lines
Fixes#2428 -- comments are no longer eatten by __future__ fixer.
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r61673 | david.wolever | 2008-03-20 17:22:40 +0100 (Do, 20 M?\195?\164r 2008) | 1 line
Added 2to3 node pretty-printer
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r61679 | david.wolever | 2008-03-20 20:50:42 +0100 (Do, 20 M?\195?\164r 2008) | 1 line
Made node printing a little bit prettier
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r61723 | martin.v.loewis | 2008-03-22 00:59:27 +0100 (Sa, 22 M?\195?\164r 2008) | 2 lines
Fix whitespace.
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r61725 | martin.v.loewis | 2008-03-22 01:02:41 +0100 (Sat, 22 Mar 2008) | 2 lines
Install lib2to3.
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r61731 | facundo.batista | 2008-03-22 03:45:37 +0100 (Sat, 22 Mar 2008) | 4 lines
Small fix that complicated the test actually when that
test failed.
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r61732 | alexandre.vassalotti | 2008-03-22 05:08:44 +0100 (Sat, 22 Mar 2008) | 2 lines
Added warning for the removal of 'hotshot' in Py3k.
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r61733 | georg.brandl | 2008-03-22 11:07:29 +0100 (Sat, 22 Mar 2008) | 4 lines
#1918: document that weak references *to* an object are
cleared before the object's __del__ is called, to ensure that the weak
reference callback (if any) finds the object healthy.
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r61734 | georg.brandl | 2008-03-22 11:56:23 +0100 (Sat, 22 Mar 2008) | 2 lines
Activate the Sphinx doctest extension and convert howto/functional to use it.
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r61735 | georg.brandl | 2008-03-22 11:58:38 +0100 (Sat, 22 Mar 2008) | 2 lines
Allow giving source names on the cmdline.
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r61737 | georg.brandl | 2008-03-22 12:00:48 +0100 (Sat, 22 Mar 2008) | 2 lines
Fixup this HOWTO's doctest blocks so that they can be run with sphinx' doctest builder.
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r61739 | georg.brandl | 2008-03-22 12:47:10 +0100 (Sat, 22 Mar 2008) | 2 lines
Test decimal.rst doctests as far as possible with sphinx doctest.
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r61741 | georg.brandl | 2008-03-22 13:04:26 +0100 (Sat, 22 Mar 2008) | 2 lines
Make doctests in re docs usable with sphinx' doctest.
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r61743 | georg.brandl | 2008-03-22 13:59:37 +0100 (Sat, 22 Mar 2008) | 2 lines
Make more doctests in pprint docs testable.
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r61744 | georg.brandl | 2008-03-22 14:07:06 +0100 (Sat, 22 Mar 2008) | 2 lines
No need to specify explicit "doctest_block" anymore.
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r61753 | georg.brandl | 2008-03-22 21:08:43 +0100 (Sat, 22 Mar 2008) | 2 lines
Fix-up syntax problems.
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r61761 | georg.brandl | 2008-03-22 22:06:20 +0100 (Sat, 22 Mar 2008) | 4 lines
Make collections' doctests executable.
(The <BLANKLINE>s will be stripped from presentation output.)
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r61765 | georg.brandl | 2008-03-22 22:21:57 +0100 (Sat, 22 Mar 2008) | 2 lines
Test doctests in datetime docs.
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r61766 | georg.brandl | 2008-03-22 22:26:44 +0100 (Sat, 22 Mar 2008) | 2 lines
Test doctests in operator docs.
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r61767 | georg.brandl | 2008-03-22 22:38:33 +0100 (Sat, 22 Mar 2008) | 2 lines
Enable doctests in functions.rst. Already found two errors :)
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r61769 | georg.brandl | 2008-03-22 23:04:10 +0100 (Sat, 22 Mar 2008) | 3 lines
Enable doctest running for several other documents.
We have now over 640 doctests that are run with "make doctest".
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r61773 | raymond.hettinger | 2008-03-23 01:55:46 +0100 (Sun, 23 Mar 2008) | 1 line
Simplify demo code.
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r61776 | neal.norwitz | 2008-03-23 04:43:33 +0100 (Sun, 23 Mar 2008) | 7 lines
Try to make this test a little more robust and not fail with:
timeout (10.0025) is more than 2 seconds more than expected (0.001)
I'm assuming this problem is caused by DNS lookup. This change
does a DNS lookup of the hostname before trying to connect, so the time
is not included.
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r61777 | neal.norwitz | 2008-03-23 05:08:30 +0100 (Sun, 23 Mar 2008) | 1 line
Speed up the test by avoiding socket timeouts.
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r61778 | neal.norwitz | 2008-03-23 05:43:09 +0100 (Sun, 23 Mar 2008) | 1 line
Skip the epoll test if epoll() does not work
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r61780 | neal.norwitz | 2008-03-23 06:47:20 +0100 (Sun, 23 Mar 2008) | 1 line
Suppress failure (to avoid a flaky test) if we cannot connect to svn.python.org
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r61781 | neal.norwitz | 2008-03-23 07:13:25 +0100 (Sun, 23 Mar 2008) | 4 lines
Move itertools before future_builtins since the latter depends on the former.
From a clean build importing future_builtins would fail since itertools
wasn't built yet.
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r61782 | neal.norwitz | 2008-03-23 07:16:04 +0100 (Sun, 23 Mar 2008) | 1 line
Try to prevent the alarm going off early in tearDown
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r61783 | neal.norwitz | 2008-03-23 07:19:57 +0100 (Sun, 23 Mar 2008) | 4 lines
Remove compiler warnings (on Alpha at least) about using chars as
array subscripts. Using chars are dangerous b/c they are signed
on some platforms and unsigned on others.
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r61788 | georg.brandl | 2008-03-23 09:05:30 +0100 (Sun, 23 Mar 2008) | 2 lines
Make the doctests presentation-friendlier.
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r61793 | amaury.forgeotdarc | 2008-03-23 10:55:29 +0100 (Sun, 23 Mar 2008) | 4 lines
#1477: ur'\U0010FFFF' raised in narrow unicode builds.
Corrected the raw-unicode-escape codec to use UTF-16 surrogates in
this case, just like the unicode-escape codec.
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r61796 | raymond.hettinger | 2008-03-23 14:32:32 +0100 (Sun, 23 Mar 2008) | 1 line
Issue 1681432: Add triangular distribution the random module.
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r61807 | raymond.hettinger | 2008-03-23 20:37:53 +0100 (Sun, 23 Mar 2008) | 4 lines
Adopt Nick's suggestion for useful default arguments.
Clean-up floating point issues by adding true division and float constants.
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r61813 | gregory.p.smith | 2008-03-23 22:04:43 +0100 (Sun, 23 Mar 2008) | 6 lines
Fix gzip to deal with CRC's being signed values in Python 2.x properly and to
read 32bit values as unsigned to start with rather than applying signedness
fixups allover the place afterwards.
This hopefully fixes the test_tarfile failure on the alpha/tru64 buildbot.
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svn+ssh://pythondev@svn.python.org/python/trunk
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r60901 | eric.smith | 2008-02-19 14:21:56 +0100 (Tue, 19 Feb 2008) | 1 line
Added PEP 3101.
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r60907 | georg.brandl | 2008-02-20 20:12:36 +0100 (Wed, 20 Feb 2008) | 2 lines
Fixes contributed by Ori Avtalion.
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r60909 | eric.smith | 2008-02-21 00:34:22 +0100 (Thu, 21 Feb 2008) | 1 line
Trim leading zeros from a floating point exponent, per C99. See issue 1600. As far as I know, this only affects Windows. Add float type 'n' to PyOS_ascii_formatd (see PEP 3101 for 'n' description).
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r60910 | eric.smith | 2008-02-21 00:39:28 +0100 (Thu, 21 Feb 2008) | 1 line
Now that PyOS_ascii_formatd supports the 'n' format, simplify the float formatting code to just call it.
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r60918 | andrew.kuchling | 2008-02-21 15:23:38 +0100 (Thu, 21 Feb 2008) | 2 lines
Close manifest file.
This change doesn't make any difference to CPython, but is a necessary fix for Jython.
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r60921 | guido.van.rossum | 2008-02-21 18:46:16 +0100 (Thu, 21 Feb 2008) | 2 lines
Remove news about float repr() -- issue 1580 is still in limbo.
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r60923 | guido.van.rossum | 2008-02-21 19:18:37 +0100 (Thu, 21 Feb 2008) | 5 lines
Removed uses of dict.has_key() from distutils, and uses of
callable() from copy_reg.py, so the interpreter now starts up
without warnings when '-3' is given. More work like this needs to
be done in the rest of the stdlib.
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r60924 | thomas.heller | 2008-02-21 19:28:48 +0100 (Thu, 21 Feb 2008) | 4 lines
configure.ac: Remove the configure check for _Bool, it is already done in the
top-level Python configure script.
configure, fficonfig.h.in: regenerated.
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r60925 | thomas.heller | 2008-02-21 19:52:20 +0100 (Thu, 21 Feb 2008) | 3 lines
Replace 'has_key()' with 'in'.
Replace 'raise Error, stuff' with 'raise Error(stuff)'.
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r60927 | raymond.hettinger | 2008-02-21 20:24:53 +0100 (Thu, 21 Feb 2008) | 1 line
Update more instances of has_key().
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r60928 | guido.van.rossum | 2008-02-21 20:46:35 +0100 (Thu, 21 Feb 2008) | 3 lines
Fix a few typos and layout glitches (more work is needed).
Move 2.5 news to Misc/HISTORY.
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r60936 | georg.brandl | 2008-02-21 21:33:38 +0100 (Thu, 21 Feb 2008) | 2 lines
#2079: typo in userdict docs.
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r60938 | georg.brandl | 2008-02-21 21:38:13 +0100 (Thu, 21 Feb 2008) | 2 lines
Part of #2154: minimal syntax fixes in doc example snippets.
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r60942 | raymond.hettinger | 2008-02-22 04:16:42 +0100 (Fri, 22 Feb 2008) | 1 line
First draft for itertools.product(). Docs and other updates forthcoming.
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r60955 | nick.coghlan | 2008-02-22 11:54:06 +0100 (Fri, 22 Feb 2008) | 1 line
Try to make command line error messages from runpy easier to understand (and suppress traceback cruft from the implicitly invoked runpy machinery)
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r60956 | georg.brandl | 2008-02-22 13:31:45 +0100 (Fri, 22 Feb 2008) | 2 lines
A lot more typo fixes by Ori Avtalion.
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r60957 | georg.brandl | 2008-02-22 13:56:34 +0100 (Fri, 22 Feb 2008) | 2 lines
Don't reference pyshell.
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r60958 | georg.brandl | 2008-02-22 13:57:05 +0100 (Fri, 22 Feb 2008) | 2 lines
Another fix.
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svn+ssh://pythondev@svn.python.org/python/trunk
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r59260 | lars.gustaebel | 2007-12-01 22:02:12 +0100 (Sat, 01 Dec 2007) | 5 lines
Issue #1531: Read fileobj from the current offset, do not seek to
the start.
(will backport to 2.5)
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r59262 | georg.brandl | 2007-12-01 23:24:47 +0100 (Sat, 01 Dec 2007) | 4 lines
Document PyEval_* functions from ceval.c.
Credits to Michael Sloan from GHOP.
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r59263 | georg.brandl | 2007-12-01 23:27:56 +0100 (Sat, 01 Dec 2007) | 2 lines
Add a few refcount data entries.
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r59264 | georg.brandl | 2007-12-01 23:38:48 +0100 (Sat, 01 Dec 2007) | 4 lines
Add test suite for cmd module.
Written by Michael Schneider for GHOP.
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r59265 | georg.brandl | 2007-12-01 23:42:46 +0100 (Sat, 01 Dec 2007) | 3 lines
Add examples to the ElementTree documentation.
Written by h4wk.cz for GHOP.
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r59266 | georg.brandl | 2007-12-02 00:12:45 +0100 (Sun, 02 Dec 2007) | 3 lines
Add "Using Python on Windows" document, by Robert Lehmann.
Written for GHOP.
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r59271 | georg.brandl | 2007-12-02 15:34:34 +0100 (Sun, 02 Dec 2007) | 3 lines
Add example to mmap docs.
Written for GHOP by Rafal Rawicki.
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r59272 | georg.brandl | 2007-12-02 15:37:29 +0100 (Sun, 02 Dec 2007) | 2 lines
Convert bdb.rst line endings to Unix style.
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r59274 | georg.brandl | 2007-12-02 15:58:50 +0100 (Sun, 02 Dec 2007) | 4 lines
Add more entries to the glossary.
Written by Jeff Wheeler for GHOP.
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meowmeowmeowcat
Andre Delfino
Daniel Fortunov
Curtis Bucher
Roger Hurwitz
Géry Ogam
Serhiy Storchaka
Mark Dickinson
Inada Naoki
Marco Buttu
Mariatta
Martin Panter
Terry Jan Reedy
Antoine Pitrou
Donald Stufft
R David Murray
Nick Coghlan
Richard Oudkerk
Raymond Hettinger
Benjamin Peterson
Collin Winter
Georg Brandl
Barry Warsaw
Christian Heimes