When the body object is a file, its size is no longer determined with
fstat(), since that can report the wrong result (e.g. reading from a pipe).
Instead, determine the size using seek(), or fall back to chunked encoding
for unseekable files.
Also, change the logic for detecting text files to check for TextIOBase
inheritance, rather than inspecting the “mode” attribute, which may not
exist (e.g. BytesIO and StringIO). The Content-Length for text files is no
longer determined ahead of time, because the original logic could have been
wrong depending on the codec and newline translation settings.
Patch by Demian Brecht and Rolf Krahl, with a few tweaks by me.
Large sections of repeated lines in tracebacks are now abbreviated as
"[Previous line repeated {count} more times]" by both the traceback
module and the builtin traceback rendering.
Patch by Emanuel Barry.
SHOW_ALLOC_COUNT or SHOW_TRACK_COUNT macros is now off by default. It can
be re-enabled using the "-X showalloccount" option. It now outputs to stderr
instead of stdout.
tkinter.Variable class. They replace old methods trace_variable, trace,
trace_vdelete and trace_vinfo that use obsolete Tcl commands and might
not work in future versions of Tcl.
modules can't be lazily loaded.
Thanks to Python 3.6 allowing for types.ModuleType to have its
__class__ mutated, the restriction can be lifted by calling
create_module() on the wrapped loader.
Issue #26249: PyMem_Malloc() allocator family now uses the pymalloc allocator
rather than system malloc(). Applications calling PyMem_Malloc() without
holding the GIL can now crash: use PYTHONMALLOC=debug environment variable to
validate the usage of memory allocators in your application.
Issue #23848: On Windows, faulthandler.enable() now also installs an exception
handler to dump the traceback of all Python threads on any Windows exception,
not only on UNIX signals (SIGSEGV, SIGFPE, SIGABRT).
Issue #26567:
* Add a new function PyErr_ResourceWarning() function to pass the destroyed
object
* Add a source attribute to warnings.WarningMessage
* Add warnings._showwarnmsg() which uses tracemalloc to get the traceback where
source object was allocated.
Issue #26564: _PyObject_DebugDumpAddress() now dumps the traceback where a
memory block was allocated on memory block. Use the tracemalloc module to get
the traceback.
Issue #26516:
* Add PYTHONMALLOC environment variable to set the Python memory
allocators and/or install debug hooks.
* PyMem_SetupDebugHooks() can now also be used on Python compiled in release
mode.
* The PYTHONMALLOCSTATS environment variable can now also be used on Python
compiled in release mode. It now has no effect if set to an empty string.
* In debug mode, debug hooks are now also installed on Python memory allocators
when Python is configured without pymalloc.
with no known parent package.
Previously SystemError was raised if the parent package didn't exist
(e.g., __package__ was set to '').
Thanks to Florent Xicluna and Yongzhi Pan for reporting the issue.
In a previous change, __spec__.parent was prioritized over
__package__. That is a backwards-compatibility break, but we do
eventually want __spec__ to be the ground truth for module details. So
this change reverts the change in semantics and instead raises an
ImportWarning when __package__ != __spec__.parent to give people time
to adjust to using spec objects.
Issue #26107: The format of the co_lnotab attribute of code objects changes to
support negative line number delta.
Changes:
* assemble_lnotab(): if line number delta is less than -128 or greater than
127, emit multiple (offset_delta, lineno_delta) in co_lnotab
* update functions decoding co_lnotab to use signed 8-bit integers
- dis.findlinestarts()
- PyCode_Addr2Line()
- _PyCode_CheckLineNumber()
- frame_setlineno()
* update lnotab_notes.txt
* increase importlib MAGIC_NUMBER to 3361
* document the change in What's New in Python 3.6
* cleanup also PyCode_Optimize() to use better variable names
not defined for a relative import.
This is the start of work to try and clean up import semantics to rely
more on a module's spec than on the myriad attributes that get set on
a module. Thanks to Rose Ames for the patch.
This was done so as to move users to `python3 -m venv` which prevents
confusion over which Python interpreter will be used in the virtual
environment when more than one is installed.
Issue #25401: Optimize bytes.fromhex() and bytearray.fromhex(): they are now
between 2x and 3.5x faster. Changes:
* Use a fast-path working on a char* string for ASCII string
* Use a slow-path for non-ASCII string
* Replace slow hex_digit_to_int() function with a O(1) lookup in
_PyLong_DigitValue precomputed table
* Use _PyBytesWriter API to handle the buffer
* Add unit tests to check the error position in error messages
Issue #25227: Optimize ASCII and latin1 encoders with the ``surrogateescape``
error handler: the encoders are now up to 3 times as fast.
Initial patch written by Serhiy Storchaka.
ignore and replace. Initial patch written by Naoki Inada.
The decoder is now up to 60 times as fast for these error handlers.
Add also unit tests for the ASCII decoder.
Martin Panter
R David Murray
Jason R. Coombs
Nick Coghlan
Serhiy Storchaka
Vinay Sajip
Berker Peksag
Brett Cannon
Steve Dower
Terry Jan Reedy
Paul Moore
Victor Stinner
Yury Selivanov
Senthil Kumaran
Zachary Ware
Raymond Hettinger
Alexander Belopolsky
Robert Collins