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.
In a Windows debug build, trying to open a file using
an empty string as the name causes assertion death
inside MS's C runtime code. We probably need to worm
around that in many places. I'm worming around it here
to stop the new test_with.py from assert-dying in the
Windows debug build (it calls compile() with an empty
string for "the file name", which indirectly leads to
C-level code in Python trying to fopen("", "r")).
If the initial import of warnings fails, clear the error. When the module
is actually needed, if the original import failed, see if it has managed
to find its way to sys.modules yet and if so, remember it.
return. Setting an exception can mess with the exception state, and
continuing is definitely wrong (since type is dereferenced later on).
Some code that calls this seems to be prepared for a NULL exception
type, so let's be safe rather than sorry and simply assume there's
nothing to normalize in this case.
PyErr_SetExcFromWindowsErr(), PyErr_SetExcFromWindowsErrWithFilename().
Similar to PyErr_SetFromWindowsErrWithFilename() and
PyErr_SetFromWindowsErr(), but they allow to specify
the exception type to raise. Available on Windows.
See SF patch #576458.
Highlights: import and friends will understand any of \r, \n and \r\n
as end of line. Python file input will do the same if you use mode 'U'.
Everything can be disabled by configuring with --without-universal-newlines.
See PEP278 for details.
Unknown whether this fixes it.
- stringobject.c, PyString_FromFormatV: don't assume that va_list is of
a type that can be copied via an initializer.
- errors.c, PyErr_Format: add a va_end() to balance the va_start().
If a new exception occurs while an exception instance is being
created, try harder to make sure there is a traceback. If the
original exception had a traceback associated with it and the new
exception does not, keep the old exception.
Of course, callers to PyErr_NormalizeException() must still be
prepared to have tb set to NULL.
XXX This isn't an ideal solution, but it's better than no traceback at
all. It occurs if, for example, the exception occurs when the call to
the constructor fails before any Python code is executed. Guido
suggests that it there is Python code that was about to be executed
-- but wasn't, say, because it was called with the wrong number of
arguments -- then we should point at the first line of the code object
anyway.
in release builds. Suggested by Martin v. Loewis.
I'm half tempted to macroize PyErr_Occurred too, as the whole thing could
collapse to just
_PyThreadState_Current->curexc_type
