This was started by Mike Bland and completed by Guido
(with help from Neal).
This still needs a __future__ statement added;
Thomas is working on Michael's patch for that aspect.
There's a small amount of code cleanup and refactoring
in ast.c, compile.c and ceval.c (I fixed the lltrace
behavior when EXT_POP is used -- however I had to make
lltrace a static global).
PyThreadState_Delete(): if the auto-GIL-state machinery knows about
the thread state, forget it (since the thread state is being deleted,
continuing to remember it can't help, but can hurt if another thread
happens to get created with the same thread id).
I'll backport to 2.4 next.
- The copy module now "copies" function objects (as atomic objects).
- dict.__getitem__ now looks for a __missing__ hook before raising
KeyError.
- Added a new type, defaultdict, to the collections module.
This uses the new __missing__ hook behavior added to dict (see above).
Based on lsprof (patch #1212837) by Brett Rosen and Ted Czotter.
With further editing by Michael Hudson and myself.
History in svn repo: http://codespeak.net/svn/user/arigo/hack/misc/lsprof
* Module/_lsprof.c is the internal C module, Lib/cProfile.py a wrapper.
* pstats.py updated to display cProfile's caller/callee timings if available.
* setup.py and NEWS updated.
* documentation updates in the profiler section:
- explain the differences between the three profilers that we have now
- profile and cProfile can use a unified documentation, like (c)Pickle
- mention that hotshot is "for specialized usage" now
- removed references to the "old profiler" that no longer exists
* test updates:
- extended test_profile to cover delicate cases like recursion
- added tests for the caller/callee displays
- added test_cProfile, performing the same tests for cProfile
* TO-DO:
- cProfile gives a nicer name to built-in, particularly built-in methods,
which could be backported to profile.
- not tested on Windows recently!
is larger than FD_SETSIZE.
This can only be acheived with ulimit -n SOME_NUMBER_BIGGER_THAN_FD_SETSIZE
which is typically only available to root. Since this wouldn't normally
be run in a test (ie, run as root), it doesn't seem too worthwhile to
add a normal test. The bug report has one version of a test. I've
written another. Not sure what the best thing to do is.
Do the check before calling internal_select() because we can't set
an error in between Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS.
This seemed the clearest solution, ie handle before calling internal_select()
rather than inside. Plus there is at least one place outside
of internal_select() that needed to be handled.
Will backport.
on both Unix (SVR4 and BSD) and Windows. Restores behaviour of passing -1
for anonymous memory on Unix. Use MAP_ANONYMOUS instead of _ANON since
the latter is deprecated according to Linux (gentoo) man pages.
Should we continue to allow mmap.mmap(0, length) to work on Windows?
0 is a valid fd.
Will backport bugfix portions.
This is how string objects work. u'%f' could use , instead of .
for the decimal point. Now both strings and unicode always use periods.
This is the code that would break:
import locale
locale.setlocale(locale.LC_NUMERIC, 'de_DE')
u'%.1f' % 1.0
assert '1.0' == u'%.1f' % 1.0
I couldn't create a test case which fails, but this fixes the problem.
Will backport.
Add C API function Py_GetBuildNumber(), add it to the interactive prompt
banner (i.e. Py_GetBuildInfo()), and add it as the sys.build_number
attribute. The build number is a string instead of an int because it may
contain a trailing 'M' if there are local modifications.
asked to read tens of megabytes of data. On my Mac, it hits MemoryErrors
when reading around 15Mb in one chunk. The fix is to read the body in several
parts, not as one big piece.
It would be nice to fix the underlying socket.read() problem, too.
2.4 bugfix candidate.
PyUnicode_DecodeCharmap() the accept a unicode string as the mapping
argument which is used as a mapping table.
This code isn't used by any of the codecs yet.
- SF Bug #772896, unknown encoding results in MemoryError, which is not helpful
I will only backport the segfault fix. I'll let Anthony decide if he wants
the other changes backported. I will do the backport if asked.
Fix segfault. I tried to write a test, but it wouldn't crash
when running regrtest. This really should have some sort of test.
Should definitely be backported.
represented as a C int, raise OverflowError.
(Forward port from 2.4.2; the patch to classobject.c was already in
but needed a correction in the error message text.)
about illegal code points. The codec now supports PEP 293 style error handlers.
(This is a variant of the Nik Haldimann's patch that detects truncated data)
even if there is an exception in later lines, resulting in
correct line numbers for decoding errors in source code. Fixes#1178484.
Will backport to 2.4.
In addition, long_pow() skipped a necessary (albeit extremely unlikely
to trigger) error check when converting an int modulus to long.
Alas, I was unable to write a test case that crashed due to either
cause.
Bugfix candidate.
[ 1229429 ] missing Py_DECREF in PyObject_CallMethod
Add a test in test_enumerate, which is a bit random, but suffices
(reversed_new calls PyObject_CallMethod under some circumstances).
managed by C, because it's possible for the block to be smaller than the
new requested size, and at the end of allocated VM. Trying to copy over
nbytes bytes to a Python small-object block can segfault then, and there's
no portable way to avoid this (we would have to know how many bytes
starting at p are addressable, and std C has no means to determine that).
Bugfix candidate. Should be backported to 2.4, but I'm out of time.
[ 1232517 ] OverflowError in time.utime() causes strange traceback
A needed error check was missing.
(Actually, this error check may only have become necessary in fairly
recent Python, not sure).
Backport candidate.
Should significantly enhance the utility of the module by supporting
the creation of tools that modify the token stream and writeback the
modified result.
[ 1180995 ] binary formats for marshalling floats
Adds 2 new type codes for marshal (binary floats and binary complexes), a
new marshal version (2), updates MAGIC and fiddles the de-serializing of
code objects to be less likely to clobber the real reason for failing if
it fails.
conversion using the proper magic slot (e.g., __int__()). Also move conversion
code out of PyNumber_*() functions in the C API into the nb_* function.
Applied patch #1109424. Thanks Walter Doewald.
byte, even if the user has passed a size parameter. This extra byte shouldn't
cause a buffer overflow in the tokenizer. The original plan was to return a line
ending in '\r', which might be recognizable as a complete line and skip any '\n'
that was read afterwards. Unfortunately this didn't work, as the tokenizer only
recognizes '\n' as line ends, which in turn lead to joined lines and
SyntaxErrors, so this special treatment of a split '\r\n' has been dropped. (It
can only happen with a temporarily exhausted bytestream now anyway.)
Fixes parts of SF bugs #1163244 and #1175396.
because (essentially) I didn't realise that PY_BEGIN/END_ALLOW_THREADS
actually expanded to nothing under a no-threads build, so if you somehow
NULLed out the threadstate (e.g. by calling PyThread_SaveThread) it would
stay NULLed when you return to Python. Argh!
Backport candidate.
instead of raising a TypeError. Allows other types to successfully
implement __radd__() style methods.
* Remove future division import from test suite.
* Remove test suite's shadowing of __builtin__.dir().
PyNumber_Check, rather than trying to convert to a float. Reimplemented
writer - now raises exceptions when it sees a quotechar but neither
doublequote or escapechar are set. Doublequote results are now more
consistent (eg, single quote should generate """", rather than "",
which is ambiguous).
_Thread.__init__) was never used. This is a waste since locks use OS
primitives that are in limited supply. So the lock is deleted in
_DummyThread.__init__ .
Closes bug #1089632.
Tools/i18n/makelocalealias.py, a tool to parse the X11 locale
alias file); the encoding lookup was enhanced to use Python's
encoding alias table
As sige-effect, this fixes SF bug [ 1080864 ] locale.py doesn't recognize
valid locale setting.
directories) and the include directories specified in CPPFLAGS (``-I``
directories) for compiling the extension modules.
This has led to the core being compiled with the values in the shell's
CPPFLAGS. It has also removed the need for special casing to use Fink and
DarwinPorts under darwin since the needed directories can now be specified in
LDFLAGS and CPPFLAGS (e.g., DarwinPorts users can now do
``LDFLAGS=-L/opt/local/lib; CPPFLAGS=-I/opt/local/include; ./configure`` for
everything to work properly).
Parsing the values in the environment variables is done with getopt. While optparse
would have been a nicer solution it cannot be used because of dependency issues
at execution time; optparse uses gettext which uses struct which will not have
been compiled when the code is imported. If optparse ever makes its
importation of gettext optional by catching ImportError and setting _() to an
identity function then it can be used.
Improve signal handling, especially when using threads, by forcing an early
re-execution of PyEval_EvalFrame() "periodic" code when things_to_do is not
cleared by Py_MakePendingCalls().
M Misc/NEWS
M Python/ceval.c
__getitem__() methods: compute only the new spellings needed to satisfy
the given indexing object. This is purely an optimization (it should
have no effect on visible semantics).
showing that doctest's pdb.set_trace() support was dramatically broken.
doctest.py _OutputRedirectingPdb.trace_dispatch(): Return a local trace
function instead of (implicitly) None. Else interaction with pdb was
bizarre, noticing only 'call' events. Amazingly, the existing set_trace()
tests didn't care.
PyGILState_Ensure(): The fix in 2.4a3 for bug 1010677 reintroduced thread
shutdown race bug 225673. Repaired by (once again) ensuring the GIL is
held whenever deleting a thread state.
Alas, there's no useful test case for this shy bug. Four years ago, only
Guido could provoke it, on his box, and today only Armin can provoke it
on his box. I've never been able to provoke it (but not for lack of
trying!).
This is a critical fix for 2.3.5 too, since the fix for 1010677 got
backported there already and so also reintroduced 225673. I don't intend to
backport this fix. For whoever (if anyone) does, there are other thread
fixes in 2.4 that need backporting too, and I bet they need to happen first
for this patch to apply cleanly.
In cyclic gc, clear weakrefs to unreachable objects before allowing any
Python code (weakref callbacks or __del__ methods) to run.
This is a critical bugfix, affecting all versions of Python since weakrefs
were introduced. I'll backport to 2.3.
Briefly (from the NEWS file):
- Updates for the email package:
+ All deprecated APIs that in email 2.x issued warnings have been removed:
_encoder argument to the MIMEText constructor, Message.add_payload(),
Utils.dump_address_pair(), Utils.decode(), Utils.encode()
+ New deprecations: Generator.__call__(), Message.get_type(),
Message.get_main_type(), Message.get_subtype(), the 'strict' argument to
the Parser constructor. These will be removed in email 3.1.
+ Support for Python earlier than 2.3 has been removed (see PEP 291).
+ All defect classes have been renamed to end in 'Defect'.
+ Some FeedParser fixes; also a MultipartInvariantViolationDefect will be
added to messages that claim to be multipart but really aren't.
+ Updates to documentation.
its documentation.
* Documented that the compiled re methods are supposed to be more full
featured than their simpilified function counterparts.
* Documented the existing start and stop position arguments for the
findall() and finditer() methods of compiled regular expression objects.
* Added an optional flags argument to the re.findall() and re.finditer()
functions. This aligns their API with that for re.search() and
re.match().
today. pyconfig.h can override it if not, and can also override
Py_IS_INFINITY now. Py_IS_NAN and Py_IS_INFINITY are overridden now
for Microsoft compilers, using efficient MS-specific spellings.
When an integer is compared to a float now, the int isn't coerced to float.
This avoids spurious overflow exceptions and insane results. This should
compute correct results, without raising spurious exceptions, in all cases
now -- although I expect that what happens when an int/long is compared to
a NaN is still a platform accident.
Note that we had potential problems here even with "short" ints, on boxes
where sizeof(long)==8. There's #ifdef'ed code here to handle that, but
I can't test it as intended. I tested it by changing the #ifdef to
trigger on my 32-bit box instead.
I suppose this is a bugfix candidate, but I won't backport it. It's
long-winded (for speed) and messy (because the problem is messy). Note
that this also depends on a previous 2.4 patch that introduced
_Py_SwappedOp[] as an extern.
decoding incomplete input (when the input stream is temporarily exhausted).
codecs.StreamReader now implements buffering, which enables proper
readline support for the UTF-16 decoders. codecs.StreamReader.read()
has a new argument chars which specifies the number of characters to
return. codecs.StreamReader.readline() and codecs.StreamReader.readlines()
have a new argument keepends. Trailing "\n"s will be stripped from the lines
if keepends is false. Added C APIs PyUnicode_DecodeUTF8Stateful and
PyUnicode_DecodeUTF16Stateful.
This checkin is adapted from part 2 (of 3) of Trevor Perrin's patch set.
BACKWARD INCOMPATIBILITY: SHIFT must now be divisible by 5. AFAIK,
nobody will care. long_pow() could be complicated to worm around that,
if necessary.
long_pow():
- BUGFIX: This leaked the base and power when the power was negative
(and so the computation delegated to float pow).
- Instead of doing right-to-left exponentiation, do left-to-right. This
is more efficient for small bases, which is the common case.
- In addition, if the exponent is large (more than FIVEARY_CUTOFF
digits), precompute [a**i % c for i in range(32)], and go left to
right 5 bits at a time.
l_divmod():
- The signature changed so that callers who don't want the quotient,
or don't want the remainder, can pass NULL in the slot they don't
want. This saves them from having to declare a vrbl for unwanted
stuff, and remembering to decref it.
long_mod(), long_div(), long_classic_div():
- Adjust to new l_divmod() signature, and simplified as a result.
This checkin is adapted from part 1 (of 3) of Trevor Perrin's patch set.
x_mul()
- sped a little by optimizing the C
- sped a lot (~2X) if it's doing a square; note that long_pow() squares
often
k_mul()
- more cache-friendly now if it's doing a square
KARATSUBA_CUTOFF
- boosted; gradeschool mult is quicker now, and it may have been too low
for many platforms anyway
KARATSUBA_SQUARE_CUTOFF
- new
- since x_mul is a lot faster at squaring now, the point at which
Karatsuba pays for squaring is much higher than for general mult
Mac-specific modules. Before all modules were compiled but would fail thanks
to a dependence on the code included when Python was built without the compiler
flag.
Closes bug #991962.
This patch includes test cases and documentation updates, as well as NEWS file
updates.
This patch also updates the sre modules so that they don't import the string
module, breaking direct circular imports.
happen in 2.3, but nobody noticed it still was getting generated (the
warning was disabled by default). OverflowWarning and
PyExc_OverflowWarning should be removed for 2.5, and left notes all over
saying so.
truncate() left the stream position unchanged, which meant the
"truncated" data didn't go away:
>>> io.write('abc')
>>> io.truncate(0)
>>> io.write('xyz')
>>> io.getvalue()
'abcxyz'
Patch by Dima Dorfman.
because GNU/k*BSD uses gnu pth to provide pthreads, but will also happen on any
system that does the same.
python fails to build because it doesn't detect gnu pth in pthread
emulation. See C comments in patch for details.
patch taken from http://bugs.debian.org/264315
path, as normalizing the path may alter the meaning of the path if it contains
symlinks.
Also add tests for infinite symlink loops and parent symlinks that need to be
resolved.
reached through a symlink (was comparing path of module to path to function and
were not matching because of the symlink). os.path.realpath() is now used to
solve this discrepency.
Closes bug #570300. Thanks Johannes Gijsbers for the fix.
interning were not clear here -- a subclass could be mutable, for
example -- and had bugs. Explicitly interning a subclass of string
via intern() will raise a TypeError. Internal operations that attempt
to intern a string subclass will have no effect.
Added a few tests to test_builtin that includes the old buggy code and
verifies that calls like PyObject_SetAttr() don't fail. Perhaps these
tests should have gone in test_string.
the tim-doctest-merge-24a2 tag on the the tim-doctest-branch branch.
We did development on the branch in case it wouldn't land in time for
2.4a2, but the branch looked good: Edward's tests passed there, ditto
Python's tests, and ditto the Zope3 tests. Together, those hit doctest
heavily.
modes like non-interactive modes. This allows for non-latin-1 users
to write unicode strings directly and sets Japanese users free from
weird manual escaping <wink> in shift_jis environments.
(Reviewed by Martin v. Loewis)
unicodedata.east_asian_width(). You can still implement your own
simple width() function using it like this:
def width(u):
w = 0
for c in unicodedata.normalize('NFC', u):
cwidth = unicodedata.east_asian_width(c)
if cwidth in ('W', 'F'): w += 2
else: w += 1
return w
or broken by basic ctype functions in 4.4BSD descendants. This
will be fixed in their future development branches but they'll keep
the POSIX-incompatibility for their backward-compatiblities in near
future.
* Fixes an incorrect variable in a PyDict_CheckExact.
* Allow general mapping locals arguments for the execfile() function
and exec statement.
* Add tests.
Major rewrite of the math module docs. Slapped in "radians" where
appropriate; grouped the functions into reasonable categories; supplied
many more words to address common confusions about some of the subtler
issues.
discussed recently in python-dev:
In _locale module:
- bind_textdomain_codeset() binding
In gettext module:
- bind_textdomain_codeset() function
- lgettext(), lngettext(), ldgettext(), ldngettext(),
which return translated strings encoded in
preferred system encoding, if
bind_textdomain_codeset() was not used.
- Added equivalent functionality in translate()
function and catalog classes.
Every change was also documented.
and Thread.__delete() was called after a Thread instance was created. Problem
resulted from a currentThread() call in an 'assert' statement being optimized
out and dummy_thread.get_ident() always returning -1 and thus overwriting the
entry for the _MainThread() instance created in 'threading' at import time.
Closes bug #993394.
__oct__, and __hex__. Raise TypeError if an invalid type is
returned. Note that PyNumber_Int and PyNumber_Long can still
return ints or longs. Fixes SF bug #966618.
and installed layouts to make maintenance simple and easy. And it
also adds four new codecs; big5hkscs, euc-jis-2004, shift-jis-2004
and iso2022-jp-2004.
I don't agree it had a bug (see the report), so this is *not* a candidate
for backporting, but the docs were confusing and the Queue implementation
was old enough to vote.
Rewrote put/put_nowait/get/get_nowait from scratch, to use a pair of
Conditions (not_full and not_empty), sharing a common mutex. The code
is 1/4 the size now, and 6.25x easier to understand. For blocking
with timeout, we also get to reuse (indirectly) the tedious timeout
code from threading.Condition. The Full and Empty exceptions raised
by non-blocking calls are now easy (instead of nearly impossible) to
explain truthfully: Full is raised if and only if the Queue truly
is full when the non-blocking put call checks the queue size, and
similarly for Empty versus non-blocking get.
What I don't know is whether the new implementation is slower (or
faster) than the old one. I don't really care. Anyone who cares
a lot is encouraged to check that.
Anthony Tuininga.
This is a derived patch, taking the opportunity to add some organization
to the now-large pile of datetime-related macros, and to factor out
tedious repeated text.
Also improved some clumsy wording in NEWS.
* Map conditions to related signals.
* Make contexts unhashable.
* Eliminate used "default" attribute in exception definitions.
* Eliminate the _filterfunc in favor of a straight list.
Docs:
* Eliminate documented references to conditions that are not signals.
* Eliminate parenthetical notes such as "1/0 --> Inf" which are no
longer true with the new defaults.
during interpreter shutdown instead of masking it with another traceback about
accessing a NoneType when trying to print the exception out in the first place.
Closes bug #754449 (using patch #954922).
- weakref.ref and weakref.ReferenceType will become aliases for each
other
- weakref.ref will be a modern, new-style class with proper __new__
and __init__ methods
- weakref.WeakValueDictionary will have a lighter memory footprint,
using a new weakref.ref subclass to associate the key with the
value, allowing us to have only a single object of overhead for each
dictionary entry (currently, there are 3 objects of overhead per
entry: a weakref to the value, a weakref to the dictionary, and a
function object used as a weakref callback; the weakref to the
dictionary could be avoided without this change)
- a new macro, PyWeakref_CheckRefExact(), will be added
- PyWeakref_CheckRef() will check for subclasses of weakref.ref
This closes SF patch #983019.
The builtin eval() function now accepts any mapping for the locals argument.
Time sensitive steps guarded by PyDict_CheckExact() to keep from slowing
down the normal case. My timings so no measurable impact.
The LaTeX is untested (well, so is the new API, for that matter).
Note that I also changed NULL to get spelled consistently in concrete.tex.
If that was a wrong thing to do, Fred should yell at me.
New include file timefuncs.h exports private API function
_PyTime_DoubleToTimet() from timemodule.c. timemodule should export
some other functions too (look for painful bits in datetimemodule.c).
Added insane-argument checking to datetime's assorted fromtimestamp()
and utcfromtimestamp() methods. Added insane-argument tests of these
to test_datetime, and insane-argument tests for ctime(), localtime()
and gmtime() to test_time.
iswide() for east asian width manipulation. (Inspired by David
Goodger, Reviewed by Martin v. Loewis)
- Move _PyUnicode_TypeRecord.flags to the end of the struct so that
no padding is added for UCS-4 builds. (Suggested by Martin v. Loewis)
(Code contributed by Jiwon Seo.)
The documentation portion of the patch is being re-worked and will be
checked-in soon. Likewise, PEP 289 will be updated to reflect Guido's
rationale for the design decisions on binding behavior (as described in
in his patch comments and in discussions on python-dev).
The test file, test_genexps.py, is written in doctest format and is
meant to exercise all aspects of the the patch. Further additions are
welcome from everyone. Please stress test this new feature as much as
possible before the alpha release.
close() calls would attempt to free() the buffer already free()ed on
the first close(). [bug introduced with patch #788249]
Making sure that the buffer is free()ed in file object deallocation is
a belt-n-braces bit of insurance against a memory leak.
array.extend() now accepts iterable arguments implements as a series
of appends. Besides being a user convenience and matching the behavior
for lists, this the saves memory and cycles that would be used to
create a temporary array object.
lists. Speeds append() operations and reduces memory requirements
(because of more conservative overallocation).
Paves the way for the feature request for array.extend() to support
arbitrary iterable arguments.
The writelines() method now accepts any iterable argument and writes
the lines one at a time rather than using ''.join(lines) followed by
a single write. Results in considerable memory savings and makes the
method suitable for use with generator expressions.
(Championed by Bob Ippolito.)
The update() method for mappings now accepts all the same argument forms
as the dict() constructor. This includes item lists and/or keyword
arguments.
are within proper boundaries as specified in the docs.
This can break possible code (datetime module needed changing, for instance)
that uses 0 for values that need to be greater 1 or greater (month, day, and
day of year).
Fixes bug #897625.
recent gcc on Linux/x86)
[ 899109 ] 1==float('nan')
by implementing rich comparisons for floats.
Seems to make comparisons involving NaNs somewhat less surprising
when the underlying C compiler actually implements C99 semantics.
to list_init.
* Replaced the code in list_extend with the superior code from list_fill.
* Eliminated list_fill.
Results:
* list.extend() no longer creates an intermediate tuple except to handle
the special case of x.extend(x). The saves memory and time.
* list.extend(x) runs
about the same x is a list or tuple,
a little faster when x is an iterable not defining __len__, and
twice as fast when x is an iterable defining __len__.
* the code is about 15 lines shorter and no longer duplicates
functionality.
The Py2.3 approach overallocated small lists by up to 8 elements.
The last checkin would limited this to one but slowed down (by 20 to 30%)
the creation of small lists between 3 to 8 elements.
This tune-up balances the two, limiting overallocation to 3 elements
(significantly reducing space consumption from Py2.3) and running faster
than the previous checkin.
The first part of the growth pattern (0, 4, 8, 16) neatly meshes with
allocators that trigger data movement only when crossing a power of two
boundary. Also, then even numbers mesh well with common data alignments.
realloc(). This is achieved by tracking the overallocation size in a new
field and using that information to skip calls to realloc() whenever
possible.
* Simplified and tightened the amount of overallocation. For larger lists,
this overallocates by 1/8th (compared to the previous scheme which ranged
between 1/4th to 1/32nd over-allocation). For smaller lists (n<6), the
maximum overallocation is one byte (formerly it could be upto eight bytes).
This saves memory in applications with large numbers of small lists.
* Eliminated the NRESIZE macro in favor of a new, static list_resize function
that encapsulates the resizing logic. Coverting this back to macro would
give a small (under 1%) speed-up. This was too small to warrant the loss
of readability, maintainability, and de-coupling.
* Some functions using NRESIZE had grown unnecessarily complex in their
efforts to bend to the macro's calling pattern. With the new list_resize
function in place, those other functions could be simplified. That is
being saved for a separate patch.
* The ob_item==NULL check could be eliminated from the new list_resize
function. This would entail finding each piece of code that sets ob_item
to NULL and adding a new line to invalidate the overallocation tracking
field. Rather than impose a new requirement on other pieces of list code,
it was preferred to leave the NULL check in place and retain the benefits
of decoupling, maintainability and information hiding (only PyList_New()
and list_sort() need to know about the new field). This approach also
reduces the odds of breaking an extension module.
(Collaborative effort by Raymond Hettinger, Hye-Shik Chang, Tim Peters,
and Armin Rigo.)
which can be reviewed via
http://coding.derkeiler.com/Archive/Python/comp.lang.python/2003-12/1011.html
Duncan Booth investigated, and discovered that an "optimisation" was
in fact a pessimisation for small numbers of elements in a source list,
compared to not having the optimisation, although with large numbers
of elements in the source list the optimisation was quite beneficial.
He posted his change to comp.lang.python (but not to SF).
Further research has confirmed his assessment that the optimisation only
becomes a net win when the source list has more than 100 elements.
I also found that the optimisation could apply to tuples as well,
but the gains only arrive with source tuples larger than about 320
elements and are nowhere near as significant as the gains with lists,
(~95% gain @ 10000 elements for lists, ~20% gain @ 10000 elements for
tuples) so I haven't proceeded with this.
The code as it was applied the optimisation to list subclasses as
well, and this also appears to be a net loss for all reasonable sized
sources (~80-100% for up to 100 elements, ~20% for more than 500
elements; I tested up to 10000 elements).
Duncan also suggested special casing empty lists, which I've extended
to all empty sequences.
On the basis that list_fill() is only ever called with a list for the
result argument, testing for the source being the destination has
now happens before testing source types.
Original idea by Guido van Rossum.
Idea for skipable inner iterators by Raymond Hettinger.
Idea for argument order and identity function default by Alex Martelli.
Implementation by Hye-Shik Chang (with tweaks by Raymond Hettinger).
comments about why both calls to cyclic gc here can cause problems.
I'll backport to 2.3 maint. Since the calls were introduced in 2.3,
that will be the end of it.
and left shifts. (Thanks to Kalle Svensson for SF patch 849227.)
This addresses most of the remaining semantic changes promised by
PEP 237, except for repr() of a long, which still shows the trailing
'L'. The PEP appears to promise warnings for operations that
changed semantics compared to Python 2.3, but this is not
implemented; we've suffered through enough warnings related to
hex/oct literals and I think it's best to be silent now.
by the function object or by the method object, the function
object's attribute usually wins. Christian Tismer pointed out that
that this is really a mistake, because this only happens for special
methods (like __reduce__) where the method object's version is
really more appropriate than the function's attribute. So from now
on, all method attributes will have precedence over function
attributes with the same name.
Also SF patch 843455.
This is a critical bugfix.
I'll backport to 2.3 maint, but not beyond that. The bugs this fixes
have been there since weakrefs were introduced.
* Install the unittests, docs, newsitem, include file, and makefile update.
* Exercise the new functions whereever sets.py was being used.
Includes the docs for libfuncs.tex. Separate docs for the types are
forthcoming.