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.
Neal Norwitz
Martin v. Löwis
Armin Rigo
Fredrik Lundh
Tim Peters
Georg Brandl
Richard Jones
Thomas Wouters
Jeremy Hylton
Anthony Baxter
Phillip J. Eby
Guido van Rossum
Hye-Shik Chang
Brett Cannon
Barry Warsaw
Michael W. Hudson
Skip Montanaro
Kurt B. Kaiser
Raymond Hettinger