Mark Dickinson [Sun, 8 Jan 2023 19:40:15 +0000 (19:40 +0000)]
gh-100833: Remove 'volatile' qualifiers in fsum algorithm (#100845)
This PR removes the `volatile` qualifier on various intermediate quantities
in the `math.fsum` implementation, and updates the notes preceding the
algorithm accordingly (as well as fixing some of the exsting notes). See
the linked issue #100833 for discussion.
- Use "drive", not "drive letter", because of UNC paths
- Previous components are not thrown away from relative drive letters
- Use "segment" instead of "component" for consistency with pathlib
- Other miscellaneous improvements
gh-91851: Micro optimizations for arithmetic between Fractions (#25518)
Adapted from
https://github.com/python/cpython/pull/24779/commits/046c84e8f9
This makes arithmetic between Fractions with small components
just as fast as before python/cpython#24779, at some expense of
mixed arithmetic (e.g. Fraction + int).
Christian Klein [Fri, 6 Jan 2023 18:38:50 +0000 (19:38 +0100)]
gh-100690: Raise an AttributeError when the assert_ prefix is forgotten when using Mock (#100691)
Mock objects which are not unsafe will now raise an AttributeError when accessing an
attribute that matches the name of an assertion but without the prefix `assert_`, e.g. accessing `called_once` instead of `assert_called_once`.
This is in addition to this already happening for accessing attributes with prefixes assert, assret, asert, aseert, and assrt.
Dustin Spicuzza [Thu, 5 Jan 2023 22:57:31 +0000 (17:57 -0500)]
gh-86082: bpo-41916: allow cross-compiled python to have -pthread set for CXX (#22525)
When cross-compiling, the compile/run test for -pthread always fails so -pthread
will never be automatically set without an override from the cache. ac_cv_pthread
can already be overridden, so do the same thing for ac_cv_cxx_thread.
Barney Gale [Thu, 5 Jan 2023 22:11:50 +0000 (22:11 +0000)]
gh-100562: improve performance of `pathlib.Path.absolute()` (GH-100563)
Increase performance of the `absolute()` method by calling `os.getcwd()` directly, rather than using the `Path.cwd()` class method. This avoids constructing an extra `Path` object (and the parsing/normalization that comes with it).
Decrease performance of the `cwd()` class method by calling the `Path.absolute()` method, rather than using `os.getcwd()` directly. This involves constructing an extra `Path` object. We do this to maintain a longstanding pattern where `os` functions are called from only one place, which allows them to be more readily replaced by users. As `cwd()` is generally called at most once within user programs, it's a good bargain.
```shell
# before
$ ./python -m timeit -s 'from pathlib import Path; p = Path("foo", "bar")' 'p.absolute()'
50000 loops, best of 5: 9.04 usec per loop
# after
$ ./python -m timeit -s 'from pathlib import Path; p = Path("foo", "bar")' 'p.absolute()'
50000 loops, best of 5: 5.02 usec per loop
```
gh-100146: Steal references from stack when building a list (#100147)
When executing the BUILD_LIST opcode, steal the references from the stack,
in a manner similar to the BUILD_TUPLE opcode. Implement this by offloading
the logic to a new private API, _PyList_FromArraySteal(), that works similarly
to _PyTuple_FromArraySteal().
This way, instead of performing multiple stack pointer adjustments while the
list is being initialized, the stack is adjusted only once and a fast memory
copy operation is performed in one fell swoop.
Ionite [Mon, 2 Jan 2023 21:11:49 +0000 (05:11 +0800)]
gh-100637: Fix int and bool __sizeof__ calculation to include the 1 element ob_digit array for 0 and False (#100663)
Fixes behaviour where int (and subtypes like bool) __sizeof__ under-reports true size as it did not take into account the size 1 `ob_digit` array for the zero int.
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
Shantanu [Mon, 2 Jan 2023 03:14:18 +0000 (20:14 -0700)]
gh-100428: Make int documentation more accurate (#100436)
- Remove first link to lexical definition of integer literal, since it
doesn't apply (differs in handling of leading zeros, base needs to be
explicitly specified, unicode digits are allowed)
- Better describe handling of leading zeros, unicode digits, underscores
- Base 0 does not work exactly as like a code literal, since it allows
Unicode digits. Link code literal to lexical definition of integer
literal.
Gregory P. Smith [Thu, 29 Dec 2022 22:41:39 +0000 (14:41 -0800)]
gh-100228: Warn from os.fork() if other threads exist. (#100229)
Not comprehensive, best effort warning. There are cases when threads exist on some platforms that this code cannot detect. macOS when API permissions allow and Linux with a readable /proc procfs present are the currently supported cases where a warning should show up reliably.
Starting with a DeprecationWarning for now, it is less disruptive than something like RuntimeWarning and most likely to only be seen in people's CI tests - a good place to start with this messaging.
It has had no effect on non-macOS platforms for a long time, and has had
the non-obvious effect of invoking `pkg_config` and not setting
`-DUSING_APPLE_OS_LIBFFI` on macOS since GH-22855.
Chris Withers [Wed, 28 Dec 2022 10:55:50 +0000 (10:55 +0000)]
Remove skipped test in test for async mocks. (#100559)
Remove skipped test.
See discussion on https://github.com/python/cpython/pull/25326.
Fix is apparently here, but no-one is confident to review and land: https://github.com/python/cpython/pull/25347.