* bpo-45514: Apply changes from importlib_resources@a3ef4128c6
* Mark legacy functions as deprecated in the docs and link to the migration docs in importlib_resources docs.
* Apply changes from importlib_resources@329ae9d5f2c.
* Indicate importlib.resources as a module.
Co-authored-by: Filipe Laíns <lains@riseup.net>
Instead we use $(PYTHON_FOR_REGEN) .../deepfreeze.py with the
frozen .h file as input, as we did for Windows in bpo-45850.
We also get rid of the code that generates the .h files
when make regen-frozen is run (i.e., .../make_frozen.py),
and the MANIFEST file.
Restore Python 3.8 and 3.9 as Windows host Python again
Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>
* Make internal APIs that take PyFrameConstructor take a PyFunctionObject instead.
* Add reference to function to frame, borrow references to builtins and globals.
* Add COPY_FREE_VARS instruction to allow specialization of calls to inner functions.
Implement changes to build with deep-frozen modules on Windows.
Note that we now require Python 3.10 as the "bootstrap" or "host" Python.
This causes a modest startup speed (around 7%) on Windows.
Special handling is needed, because for non-slots dataclasses the instance attributes are not set: reading from a field just references the class's attribute of the same name, which contains the default value. But this doesn't work for classes using __slots__: they don't read the class's attribute. So in that case (and that case only), initialize the instance attribute. Handle this for both normal defaults, and for fields using default_factory.
It is now considered a historical accident that e.g. `for` loops and the `iter()` built-in function do not require the iterators they work with to define `__iter__`, only `__next__`.
Some of the tests in test_queue had a race condition in which a
non-sentinel value could be enqueued after the final sentinel value
leading to not all the inputs being processed (and test failures).
This changes feed() to enqueue a sentinel once the inputs are exhausted,
which guarantees that the final queued object is a sentinel. This
requires the number of feeder threads to match the number of consumer
threads, but that's already the case in the relevant tests.
``configure`` now uses a standardized format to forward state, compiler
flags, and linker flags to ``Makefile``, ``setup.py``, and
``Modules/Setup``. ``makesetup`` use the new variables by default if a
module line does not contain any compiler or linker flags. ``setup.py``
has a new function ``addext()``.
For a module ``egg``, configure adds:
* ``MODULE_EGG`` with value yes, missing, disabled, or n/a
* ``MODULE_EGG_CFLAGS``
* ``MODULE_EGG_LDFLAGS``
``Makefile.pre.in`` may also provide ``MODULE_EGG_DEPS`` that lists
dependencies such as header files and static libs.
Signed-off-by: Christian Heimes <christian@python.org>
Unlike the other locks reinitialized by _PyRuntimeState_ReInitThreads,
the "interpreters.main->id_mutex" is not freed by _PyRuntimeState_Fini
and should not force the default raw allocator.
Continue with the improvement of the library netrc
Original work and report Xiang Zhang <angwerzx@126.com>
* 📜🤖 Added by blurb_it.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Remove the asyncore and asynchat modules, deprecated in Python
3.6: use the asyncio module instead.
Remove the smtpd module, deprecated in Python 3.6: the aiosmtpd
module can be used instead, it is based on asyncio.
* Remove asyncore, asynchat and smtpd documentation
* Remove test_asyncore, test_asynchat and test_smtpd
* Rename Lib/asynchat.py to Lib/test/support/_asynchat.py
* Rename Lib/asyncore.py to Lib/test/support/_asyncore.py
* Rename Lib/smtpd.py to Lib/test/support/_smtpd.py
* Remove DeprecationWarning from private _asyncore, _asynchat and
_smtpd modules
* _smtpd: remove deprecated properties
* bpo-25381: Update explanation of exception globals
This paragraph in extending/extending.rst was unchanged (except for
NULL markup) since committed in 2007 Aug 15 for 2.6 alpha.
* Respond to reviews and remove duplication.
* Update Doc/extending/extending.rst
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Settings for :mod:`pyexpat` C extension are now detected by ``configure``.
The bundled ``expat`` library is built in ``Makefile``.
Signed-off-by: Christian Heimes <christian@python.org>
Settings for :mod:`decimal` internal C extension are now detected by
:program:`configure`. The bundled `libmpdec` library is built in
``Makefile``.
Signed-off-by: Christian Heimes <christian@python.org>
* bpo-45772: socket.socket should be a class instead of a function
Currently `socket.socket` is documented as a function, but it is really
a class (and thus has function-like usage to construct an object). This
correction would ensure that Python projects that are interlinking
Python's documentation can properly locate `socket.socket` as a type.
Remove the --findleaks command line option of regrtest: use the
--fail-env-changed option instead. Since Python 3.7, it was a
deprecated alias to the --fail-env-changed option.
This gains 10% or more in startup time for `python -c pass` on UNIX-ish systems.
The Makefile.pre.in generating code builds on Eric's work for bpo-45020, but the .c file generator is new.
Windows version TBD.
Almost all checks are now cached by AC_CACHE_CHECK().
Common patterns are replaced by helper macros.
Variable names now use naming scheme ``ac_cv_func_$funcname``,
``ac_cv_lib_$library_$funcname``, or ``ac_cv_header_$headername_h``.
``SYS_SELECT_WITH_SYS_TIME`` is no longer used.
``uuid_create`` and ``uuid_enc_be`` are provided by libc on BSD. It is
safe to use ``AC_CHECK_FUNCS`` here.
Caching speeds up ./configure -C from ~ 4s to 2.6s on my system.
Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>
In order to fix a bug in the 3.9 branch in #29394, more tests were added to
``test_functools.py`` to ensure that ``singledispatchmethod`` still correctly
wrapped a target method, even if the target method had already been wrapped by
multiple other decorators. This PR brings the new tests into the 3.11 and 3.10
branches as well.
Some test cases don't work when test modules are static extensions.
Add dependency on Modules/config.c to trigger a rebuild whenever a
module build type is changed.
``makesetup`` puts shared extensions into ``Modules/`` directory. Create
symlinks from pybuilddir so the extensions can be imported.
Note: It is not possible to use the content of pybuilddir.txt as a build
target. Makefile evaluates target variables in the first pass. The
pybuilddir.txt file does not exist at that point.
Currently custom modules (the array set on PyImport_FrozenModules) replace all the frozen stdlib modules. That can be problematic and is unlikely to be what the user wants. This change treats the custom frozen modules as additions instead. They take precedence over all other frozen modules except for those needed to bootstrap the import system. If the "code" field of an entry in the custom array is NULL then that frozen module is treated as disabled, which allows a custom entry to disable a frozen stdlib module.
This change allows us to get rid of is_essential_frozen_module() and simplifies the logic for which frozen modules should be ignored.
https://bugs.python.org/issue45395
The list of PEPs at the top of the documentation for the ``typing`` module has
become too long to be readable. This PR proposes presenting this
information in a more structured and readable way by adding a new "relevant
PEPs" section to the ``typing`` docs.
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
The doctest module raised an error if a docstring contained an example that
attempted to access a classmethod property. (Stacking '@classmethod' on top of
`@property` has been supported since Python 3.9; see
https://docs.python.org/3/howto/descriptor.html#class-methods.)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Use types.GenericAlias in inspect.formatannotation to correctly add
type arguments of builtin types to the string representation of
Signatures.
Co-authored-by: Martin Rückl <martin.rueckl@codecentric.de>
``setup.py`` and ``makesetup`` now track build dependencies on all Python
header files and module specific header files.
Signed-off-by: Christian Heimes <christian@python.org>
The :mod:`math` and :mod:`cmath` implementation now require a C99 compatible
``libm`` and no longer ship with workarounds for missing acosh, asinh,
expm1, and log1p functions.
The changeset also removes ``_math.c`` and moves the last remaining
workaround into ``_math.h``. This simplifies static builds with
``Modules/Setup`` and resolves symbol conflicts.
Co-authored-by: Mark Dickinson <mdickinson@enthought.com>
Co-authored-by: Brett Cannon <brett@python.org>
Signed-off-by: Christian Heimes <christian@python.org>
Keep track of whether unsafe_tuple_compare() calls are resolved by the very
first tuple elements, and adjust strategy accordingly. This can significantly
cut the number of calls made to the full-blown PyObject_RichCompareBool(),
and especially when duplicates are rare.
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
* ``HAVE_EXPAT_CONFIG_H`` is not used by our code and not used by
system-wide expat header files
* ``USE_PYEXPAT_CAPI`` is no longer used by our code
* ``XML_POOR_ENTROPY`` should be defined in expat_config.h
Signed-off-by: Christian Heimes <christian@python.org>
setup.py no longer defines Py_BUILD_CORE_MODULE. Instead every
module defines the macro before #include "Python.h" unless
Py_BUILD_CORE_BUILTIN is already defined.
Py_BUILD_CORE_BUILTIN is defined for every module that is built by
Modules/Setup.
The PR also simplifies Modules/Setup. Makefile and makesetup
already define Py_BUILD_CORE_BUILTIN and include Modules/internal
for us.
Signed-off-by: Christian Heimes <christian@python.org>
MAP_BOT_LENGTH was incorrectly used to compute MAP_TOP_MASK instead of
MAP_TOP_LENGTH. On 64-bit machines, the error causes the tree to hold
46-bits of virtual addresses, rather than the intended 48-bits.
Freelists for object structs can now be disabled. A new ``configure``
option ``--without-freelists`` can be used to disable all freelists
except empty tuple singleton. Internal Py*_MAXFREELIST macros can now
be defined as 0 without causing compiler warnings and segfaults.
Signed-off-by: Christian Heimes <christian@python.org>
Rename namespace package __loader__ class to be public.
Make the old name, i.e. _NamespaceLoader, an alias for the public name, for backward compatibility.
An object implementing the os.PathLike protocol can represent a file
system path as a str or bytes object.
Therefore, _infer_return_type function should infer os.PathLike[str]
object as str type and os.PathLike[bytes] object as bytes type.
Also, reword the What's New messages: this doesn't change the limited API, it only brings the Py_LIMITED_API macro closer to the ideal of only allowing the limited API.
Automerge-Triggered-By: GH:encukou
Added non parallel-safe :func:`~contextlib.chdir` context manager to change
the current working directory and then restore it on exit. Simple wrapper
around :func:`~os.chdir`.
Signed-off-by: Filipe Laíns <lains@riseup.net>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
In Python 3.8 and 3.9, stacking `@functools.singledispatchmethod` on top of
`@classmethod` or `@staticmethod` caused an exception to be raised if the
method was registered using type-annotations rather than
`@method.register(int)`. This was not caught by unit tests, however, as the
tests only tested the `@method.register(int)` way of registering additional
implementations. The bug is no longer present in Python 3.10+, but
`test_functools.py` is still lacking regression tests for these cases. This
commit adds these test cases.
There are two errors that this commit fixes:
* The parser was not correctly computing the offset and the string
source for E_LINECONT errors due to the incorrect usage of strtok().
* The parser was not correctly unwinding the call stack when a tokenizer
exception happened in rules involving optionals ('?', [...]) as we
always make them return valid results by using the comma operator. We
need to check first if we don't have an error before continuing.
I considered only falling back when both were 0, but that still seems
wrong, and the highly popular rich[1] library does it this way, so I
thought we should probably inherit that behavior.
[1] https://github.com/willmcgugan/rich
Signed-off-by: Filipe Laíns <lains@riseup.net>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
The Python 3.11 limited C API no longer includes stdlib.h, stdio.h,
string.h and errno.h.
* Exclude Py_MEMCPY() from Python 3.11 limited C API.
* xxlimited C extension is now built with Python 3.11 limited C API.
Split header files to move the non-limited API to Include/cpython/:
* Include/warnings.h => Include/cpython/warnings.h
* Include/weakrefobject.h => Include/cpython/weakrefobject.h
Exclude PyWeakref_GET_OBJECT() from the limited C API. It never
worked since the PyWeakReference structure is opaque in the limited C
API.
Move _PyWarnings_Init() and _PyErr_WarnUnawaitedCoroutine() to the
internal C API.
* bpo-45516: add protocol description to the Traversable documentation
Signed-off-by: Filipe Laíns <lains@riseup.net>
* Update Doc/library/importlib.rst
Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>
* Update Lib/importlib/abc.py
* Update Doc/library/importlib.rst
Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>
Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>
The default was "off". Switching it to "on" means users get the benefit of frozen stdlib modules without having to do anything. There's a special-case for running-in-source-tree, so contributors don't get surprised when their stdlib changes don't get used.
https://bugs.python.org/issue45020
Remove fallbacks for missing round(), copysign() and hypot() in
Python/pymath.c. Python now requires these functions to build.
These fallbacks were needed on Visual Studio 2012 and older. They are
no longer needed since Visual Stuido 2013. Python is now built with
Visual Studio 2017 or newer since Python 3.6.
Add PyThreadState_EnterTracing() and PyThreadState_LeaveTracing()
functions to the limited C API to suspend and resume tracing and
profiling.
Add an unit test on the PyThreadState C API to _testcapi.
Add also internal _PyThreadState_DisableTracing() and
_PyThreadState_ResetTracing().
Move classobject.h, context.h, genobject.h and longintrepr.h header
files from Include/ to Include/cpython/.
Remove redundant "#ifndef Py_LIMITED_API" in context.h.
Remove explicit #include "longintrepr.h" in C files. It's not needed,
Python.h already includes it.
Remove two functions from the limited C API:
* PyMarshal_WriteLongToFile()
* PyMarshal_WriteObjectToFile()
The PEP 384 excludes functions expecting "FILE*" from the stable ABI.
Remove also the Py_MARSHAL_VERSION macro from the limited C API.
Currently frozen modules do not have __file__ set. In their spec, origin is set to "frozen" and they are marked as not having a location. (Similarly, for frozen packages __path__ is set to an empty list.) However, for frozen stdlib modules we are able to extrapolate __file__ as long as we can determine the stdlib directory at runtime. (We now do so since gh-28586.) Having __file__ set is helpful for a number of reasons. Likewise, having a non-empty __path__ means we can import submodules of a frozen package from the filesystem (e.g. we could partially freeze the encodings module).
This change sets __file__ (and adds to __path__) for frozen stdlib modules. It uses sys._stdlibdir (from gh-28586) and the frozen module alias information (from gh-28655). All that work is done in FrozenImporter (in Lib/importlib/_bootstrap.py).
Also, if a frozen module is imported before importlib is bootstrapped (during interpreter initialization) then we fix up that module and its spec during the importlib bootstrapping step (i.e. imporlib._bootstrap._setup()) to match what gets set by FrozenImporter, including setting the file info (if the stdlib dir is known). To facilitate this, modules imported using PyImport_ImportFrozenModule() have __origname__ set using the frozen module alias info. __origname__ is popped off during importlib bootstrap.
(To be clear, even with this change the new code to set __file__ during fixups in imporlib._bootstrap._setup() doesn't actually get triggered yet. This is because sys._stdlibdir hasn't been set yet in interpreter initialization at the point importlib is bootstrapped. However, we do fix up such modules at that point to otherwise match the result of importing through FrozenImporter, just not the __file__ and __path__ parts. Doing so will require changes in the order in which things happen during interpreter initialization. That can be addressed separately. Once it is, the file-related fixup code from this PR will kick in.)
Here are things this change does not do:
* set __file__ for non-stdlib modules (no way of knowing the parent dir)
* set __file__ if the stdlib dir is not known (nor assume the expense of finding it)
* relatedly, set __file__ if the stdlib is in a zip file
* verify that the filename set to __file__ actually exists (too expensive)
* update __path__ for frozen packages that alias a non-package (since there is no package dir)
Other things this change skips, but we may do later:
* set __file__ on modules imported using PyImport_ImportFrozenModule()
* set co_filename when we unmarshal the frozen code object while importing the module (e.g. in FrozenImporter.exec_module()) -- this would allow tracebacks to show source lines
* implement FrozenImporter.get_filename() and FrozenImporter.get_source()
https://bugs.python.org/issue21736
Creating an Enum exhibited quadratic behavior based on the number of members in three places:
- `EnumDict._member_names`: a list searched with each new member's name
- member creation: a `for` loop checking each existing member to see if new member was a duplicate
- `auto()` values: a list of all previous values in enum was copied before being sent to `_generate_next_value()`
Two of those issues have been resolved:
- `_EnumDict._member_names` is now a dictionary so lookups are fast
- member creation tries a fast value lookup before falling back to the slower `for` loop lookup
The third issue still remains, as `_generate_next_value_()` can be user-overridden and could corrupt the last values list if it were not copied.
They support now splitting escape sequences between input chunks.
Add the third parameter "final" in codecs.raw_unicode_escape_decode().
It is True by default to match the former behavior.
They support now splitting escape sequences between input chunks.
Add the third parameter "final" in codecs.unicode_escape_decode().
It is True by default to match the former behavior.
Building Python now requires a C99 <math.h> header file providing
isinf(), isnan() and isfinite() functions.
Remove the Py_FORCE_DOUBLE() macro. It was used by the
Py_IS_INFINITY() macro.
Changes:
* Remove Py_IS_NAN(), Py_IS_INFINITY() and Py_IS_FINITE()
in PC/pyconfig.h.
* Remove the _Py_force_double() function.
* configure no longer checks if math.h defines isinf(), isnan() and
isfinite().
At import time, the xmlrpc.client module uses different date formats to
test strftime so it can format years with 4 digits consistently.
Depending on the underlying C library and its strftime implementation
some of these calls can result in ValueErrors, blocking the
xmlrpc.client module from being imported.
This commit changes the behavior of this bit of code to react to
ValueError exceptions, treating the format that caused them as an
non-viable option.
Move Include/pystrhex.h to Include/internal/pycore_strhex.h.
The header file only contains private functions.
The following C extensions are now built with Py_BUILD_CORE_MODULE
macro defined to get access to the internal C API:
* _blake2
* _hashopenssl
* _md5
* _sha1
* _sha3
* _ssl
* binascii
* Never change types' cached keys. It could invalidate inline attribute objects.
* Lazily create object dictionaries.
* Update specialization of LOAD/STORE_ATTR.
* Don't update shared keys version for deletion of value.
* Update gdb support to handle instance values.
* Rename SPLIT_KEYS opcodes to INSTANCE_VALUE.
Change the configure logic to function properly on macOS when the compiler
outputs a platform triplet for option --print-multiarch.
Co-authored-by: Ned Deily <nad@python.org>
Remove the following math macros using the errno variable:
* Py_ADJUST_ERANGE1()
* Py_ADJUST_ERANGE2()
* Py_OVERFLOWED()
* Py_SET_ERANGE_IF_OVERFLOW()
* Py_SET_ERRNO_ON_MATH_ERROR()
Create pycore_pymath.h internal header file.
Rename Py_ADJUST_ERANGE1() and Py_ADJUST_ERANGE2() to
_Py_ADJUST_ERANGE1() and _Py_ADJUST_ERANGE2(), and convert these
macros to static inline functions.
Move the following macros to pycore_pymath.h:
* _Py_IntegralTypeSigned()
* _Py_IntegralTypeMax()
* _Py_IntegralTypeMin()
* _Py_InIntegralTypeRange()
When libregrtest spawns a worker process, stderr is now written into
stdout to keep messages order. Use a single pipe for stdout and
stderr, rather than two pipes. Previously, messages were out of order
which made analysis of buildbot logs harder
Fix test_name_error_suggestions_do_not_trigger_for_too_many_locals()
of test_exceptions if a directory name contains "a1" (like
"Python-3.11.0a1"): use a stricter regular expression.
* Support HTTP response status code 308 in urllib.
HTTP response status code 308 is defined in https://tools.ietf.org/html/rfc7538 to be the permanent redirect variant of 307 (temporary redirect).
* Update documentation to include http_error_308()
* Add blurb for bpo-40321 fix
Co-authored-by: Roland Crosby <roland@rolandcrosby.com>
In the list of generated frozen modules at the top of Tools/scripts/freeze_modules.py, you will find that some of the modules have a different name than the module (or .py file) that is actually frozen. Let's call each case an "alias". Aliases do not come into play until we get to the (generated) list of modules in Python/frozen.c. (The tool for freezing modules, Programs/_freeze_module, is only concerned with the source file, not the module it will be used for.)
Knowledge of which frozen modules are aliases (and the identity of the original module) normally isn't important. However, this information is valuable when we go to set __file__ on frozen stdlib modules. This change updates Tools/scripts/freeze_modules.py to map aliases to the original module name (or None if not a stdlib module) in Python/frozen.c. We also add a helper function in Python/import.c to look up a frozen module's alias and add the result of that function to the frozen info returned from find_frozen().
https://bugs.python.org/issue45020
Before this change we end up duplicating effort and throwing away data in FrozenImporter.find_spec(). Now we do the work once in find_spec() and the only thing we do in FrozenImporter.exec_module() is turn the raw frozen data into a code object and then exec it.
We've added _imp.find_frozen(), add an arg to _imp.get_frozen_object(), and updated FrozenImporter. We've also moved some code around to reduce duplication, get a little more consistency in outcomes, and be more efficient.
Note that this change is mostly necessary if we want to set __file__ on frozen stdlib modules. (See https://bugs.python.org/issue21736.)
https://bugs.python.org/issue45324
* bpo-44594: fix (Async)ExitStack handling of __context__
Make enter_context(foo()) / enter_async_context(foo()) equivalent to
`[async] with foo()` regarding __context__ when an exception is raised.
Previously exceptions would be caught and re-raised with the wrong
context when explicitly overriding __context__ with None.
WaitForSingleObject() accepts timeout in milliseconds in the range
[0; 0xFFFFFFFE] (DWORD type). INFINITE value (0xFFFFFFFF) means no
timeout. 0xFFFFFFFE milliseconds is around 49.7 days.
PY_TIMEOUT_MAX is (0xFFFFFFFE * 1000) milliseconds on Windows, around
49.7 days.
Partially revert commit 37b8294d62.
On Unix, if the sem_clockwait() function is available in the C
library (glibc 2.30 and newer), the threading.Lock.acquire() method
now uses the monotonic clock (time.CLOCK_MONOTONIC) for the timeout,
rather than using the system clock (time.CLOCK_REALTIME), to not be
affected by system clock changes.
configure now checks if the sem_clockwait() function is available.
* Work correctly if an additional fresh module imports other
additional fresh module which imports a blocked module.
* Raises ImportError if the specified module cannot be imported
while all additional fresh modules are successfully imported.
* Support blocking packages.
* Always restore the import state of fresh and blocked modules
and their submodules.
* Fix test_decimal and test_xml_etree which depended on an undesired
side effect of import_fresh_module().
PyThread_acquire_lock_timed() now clamps the timeout into the
[_PyTime_MIN; _PyTime_MAX] range (_PyTime_t type) if it is too large,
rather than calling Py_FatalError() which aborts the process.
PyThread_acquire_lock_timed() no longer uses
MICROSECONDS_TO_TIMESPEC() to compute sem_timedwait() argument, but
_PyTime_GetSystemClock() and _PyTime_AsTimespec_truncate().
Fix _thread.TIMEOUT_MAX value on Windows: the maximum timeout is
0x7FFFFFFF milliseconds (around 24.9 days), not 0xFFFFFFFF
milliseconds (around 49.7 days).
Set PY_TIMEOUT_MAX to 0x7FFFFFFF milliseconds, rather than 0xFFFFFFFF
milliseconds.
Fix PY_TIMEOUT_MAX overflow test: replace (us >= PY_TIMEOUT_MAX) with
(us > PY_TIMEOUT_MAX).
* during tarfile parsing, a zlib error indicates invalid data
* tarfile.open now raises a descriptive exception from the zlib error
* this makes it clear to the user that they may be trying to open a
corrupted tar file
Fix the threading._shutdown() function when the threading module was
imported first from a thread different than the main thread: no
longer log an error at Python exit.
Fix a race condition in the Thread.join() method of the threading
module. If the function is interrupted by a signal and the signal
handler raises an exception, make sure that the thread remains in a
consistent state to prevent a deadlock.
Having `operator.call(obj, arg)` mean `type(obj).__call__(obj, arg)` is
consistent with the other dunder operators. The semantics with `*args,
**kwargs` then follow naturally from the single-arg semantics.
