Allows dictionaries to be pre-sized (upto 255 elements) saving time lost
to re-sizes with their attendant mallocs and re-insertions.
Has zero effect on small dictionaries (5 elements or fewer), a slight
benefit for dicts upto 22 elements (because they had to resize once
anyway), and more benefit for dicts upto 255 elements (saving multiple
resizes during the build-up and reducing the number of collisions on
the first insertions). Beyond 255 elements, there is no addional benefit.
Correction for issue1265 (pdb bug with "with" statement).
When an unfinished generator-iterator is garbage collected, PyEval_EvalFrameEx
is called with a GeneratorExit exception set. This leads to funny results
if the sys.settrace function itself makes use of generators.
A visible effect is that the settrace function is reset to None.
Another is that the eventual "finally" block of the generator is not called.
It is necessary to save/restore the exception around the call to the trace
function.
This happens a lot with py3k: isinstance() of an ABCMeta instance runs
def __instancecheck__(cls, instance):
"""Override for isinstance(instance, cls)."""
return any(cls.__subclasscheck__(c)
for c in {instance.__class__, type(instance)})
which lets an opened generator expression each time it returns True.
Backport candidate, even if the case is less frequent in 2.5.
I can't think of an easy way to test this behavior. It only occurs
when the file system default encoding and the interpreter default
encoding are different, such that you can open the file but not decode
its name.
The next step of PEP 352 (for 2.6) causes raising a string exception to trigger
a TypeError. Trying to catch a string exception raises a DeprecationWarning.
References to string exceptions has been removed from the docs since they are
now just an error.
I modified this patch some by fixing style, some error checking, and adding
XXX comments. This patch requires review and some changes are to be expected.
I'm checking in now to get the greatest possible review and establish a
baseline for moving forward. I don't want this to hold up release if possible.
set_exc_info(), reset_exc_info(): By exploiting the
likely (who knows?) invariant that when an exception's
`type` is NULL, its `value` and `traceback` are also NULL,
save some cycles in heavily-executed code.
This is a "a kronar saved is a kronar earned" patch: the
speedup isn't reliably measurable, but it obviously does
reduce the operation count in the normal (no exception
raised) path through PyEval_EvalFrameEx().
The tim-exc_sanity branch tries to push this harder, but
is still blowing up (at least in part due to pre-existing
subtle bugs that appear to have no other visible
consequences!).
Not a bugfix candidate.
that are suspended outside of any try/except/finally blocks to be
garbage collected even if they are part of a cycle. Generators that
suspend inside of an active try/except or try/finally block (including
those created by a ``with`` statement) are still not GC-able if they
are part of a cycle, however.
Anyway, this is the changes to the with-statement
so that __exit__ must return a true value in order
for a pending exception to be ignored.
The PEP (343) is already updated.
added message attribute compared to the previous version of Exception. It is
also a new-style class, making all exceptions now new-style. KeyboardInterrupt
and SystemExit inherit from BaseException directly. String exceptions now
raise DeprecationWarning.
Applies patch 1104669, and closes bugs 1012952 and 518846.
- New semantics for __exit__() -- it must re-raise the exception
if type is not None; the with-statement itself doesn't do this.
(See the updated PEP for motivation.)
- Added context managers to:
- file
- thread.LockType
- threading.{Lock,RLock,Condition,Semaphore,BoundedSemaphore}
- decimal.Context
- Added contextlib.py, which defines @contextmanager, nested(), closing().
- Unit tests all around; bot no docs yet.
- IMPORT_NAME takes an extra argument from the stack: the relativeness of
the import. Only passed to __import__ when it's not -1.
- __import__() takes an optional 5th argument for the same thing; it
__defaults to -1 (old semantics: try relative, then absolute)
- 'from . import name' imports name (be it module or regular attribute)
from the current module's *package*. Likewise, 'from .module import name'
will import name from a sibling to the current module.
- Importing from outside a package is not allowed; 'from . import sys' in a
toplevel module will not work, nor will 'from .. import sys' in a
(single-level) package.
- 'from __future__ import absolute_import' will turn on the new semantics
for import and from-import: imports will be absolute, except for
from-import with dots.
Includes tests for regular imports and importhooks, parser changes and a
NEWS item, but no compiler-package changes or documentation changes.
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).
In C++, it's an error to pass a string literal to a char* function
without a const_cast(). Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.
I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc. Predictably, there were a large set of functions that
needed to be fixed as a result of these changes. The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].
One cast was required as a result of the changes: A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.
This change implements a new bytecode compiler, based on a
transformation of the parse tree to an abstract syntax defined in
Parser/Python.asdl.
The compiler implementation is not complete, but it is in stable
enough shape to run the entire test suite excepting two disabled
tests.
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
High level error message was stomping useful detailed messages from lower
level routines.
The new approach is to augment string error messages returned by the low
level routines. The provides both high and low level information. If
the exception value is not a string, no changes are made.
To see the improved messages in action, type:
import random
class R(random): pass
class B(bool): pass
hack: it would resize *interned* strings in-place! This occurred because
their reference counts do not have their expected value -- stringobject.c
hacks them. Mea culpa.
have differing refcount semantics. If anyone sees a prettier way to
acheive the same ends, then please go for it.
I think this is the first time I've ever used Py_XINCREF.
* Fixes an incorrect variable in a PyDict_CheckExact.
* Allow general mapping locals arguments for the execfile() function
and exec statement.
* Add tests.
[ 960406 ] unblock signals in threads
although the changes do not correspond exactly to any patch attached to
that report.
Non-main threads no longer have all signals masked.
A different interface to readline is used.
The handling of signals inside calls to PyOS_Readline is now rather
different.
These changes are all a bit scary! Review and cross-platform testing
much appreciated.
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.
Guido van Rossum
Nick Coghlan
Jeffrey Yasskin
Neal Norwitz
Christian Heimes
Raymond Hettinger
Georg Brandl
Amaury Forgeot d'Arc
Thomas Wouters
Martin v. Löwis
Kristján Valur Jónsson
Jeremy Hylton
Brett Cannon
Armin Rigo
Andrew M. Kuchling
Fredrik Lundh
Tim Peters
Richard Jones
Anthony Baxter
Phillip J. Eby
Hye-Shik Chang
Barry Warsaw
Michael W. Hudson
Skip Montanaro
Kurt B. Kaiser
Nicholas Bastin