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Fix outdated note about 'int' rounding or truncating #102736

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mdickinson merged 1 commit into from
Mar 16, 2023
Merged

Fix outdated note about 'int' rounding or truncating #102736

mdickinson merged 1 commit into from
Mar 16, 2023

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@mdickinson mdickinson commented Mar 15, 2023 •
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This PR fixes an out-of-date note attached to int conversions in stdtypes.rst.

The "may round or truncate as in C" language dates from almost 30 years ago, when conversion from a Python float to a Python int involved at C level a (long) cast applied to a C double value. Prior to standard C, presumably the precise behaviour of that cast couldn't be relied upon. But since C89 standardised this behaviour and we can reasonably rely on all current C compilers adhering to that or later standards, the note is out of date. (Moreover, the current code for converting a Python 3 int to a C double is very different.)

Related discuss.python.org thread: https://discuss.python.org/t/built-in-types-int-round-or-truncate-please-elaborate/24840

@bedevere-bot bedevere-bot added docs Documentation in the Doc dir awaiting core review labels Mar 15, 2023
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terryjreedy commented Mar 16, 2023

Mark, tests are complete, so this is ready to merge and backport.

@mdickinson mdickinson merged commit 405739f into python:main Mar 16, 2023
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miss-islington commented Mar 16, 2023

Thanks @mdickinson for the PR 🌮🎉.. I'm working now to backport this PR to: 3.10, 3.11.
🐍🍒⛏🤖

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bedevere-bot commented Mar 16, 2023

GH-102766 is a backport of this pull request to the 3.11 branch.

@bedevere-bot bedevere-bot removed the needs backport to 3.11 only security fixes label Mar 16, 2023
miss-islington pushed a commit to miss-islington/cpython that referenced this pull request Mar 16, 2023
@mdickinson @miss-islington
Fix outdated note about 'int' rounding or truncating (pythonGH-102736)
6836408 
(cherry picked from commit 405739f)

Co-authored-by: Mark Dickinson <[email protected]>
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bedevere-bot commented Mar 16, 2023

GH-102767 is a backport of this pull request to the 3.10 branch.

@bedevere-bot bedevere-bot removed the needs backport to 3.10 only security fixes label Mar 16, 2023
miss-islington pushed a commit to miss-islington/cpython that referenced this pull request Mar 16, 2023
@mdickinson @miss-islington
Fix outdated note about 'int' rounding or truncating (pythonGH-102736)
dd08b6c 
(cherry picked from commit 405739f)

Co-authored-by: Mark Dickinson <[email protected]>
@mdickinson mdickinson deleted the fix-outdated-round-or-truncate-language branch March 16, 2023 20:35
mdickinson added a commit that referenced this pull request Mar 16, 2023
@miss-islington @mdickinson
[3.11] Fix outdated note about 'int' rounding or truncating (GH-102736)…
df399a3 
… (#102766)

Fix outdated note about 'int' rounding or truncating (GH-102736)
(cherry picked from commit 405739f)

Co-authored-by: Mark Dickinson <[email protected]>
mdickinson added a commit that referenced this pull request Mar 16, 2023
@miss-islington @mdickinson
[3.10] Fix outdated note about 'int' rounding or truncating (GH-102736)…
99b38be 
… (#102767)

Fix outdated note about 'int' rounding or truncating (GH-102736)
(cherry picked from commit 405739f)

Co-authored-by: Mark Dickinson <[email protected]>
carljm added a commit to carljm/cpython that referenced this pull request Mar 17, 2023
@carljm
Merge branch 'main' into inlinecomp2
1a8f4a0 
* main: (34 commits)
  pythongh-102701: Fix overflow in dictobject.c (pythonGH-102750)
  pythonGH-78530: add support for generators in `asyncio.wait` (python#102761)
  Increase stack reserve size for Windows debug builds to avoid test crashes (pythonGH-102764)
  pythongh-102755: Add PyErr_DisplayException(exc) (python#102756)
  Fix outdated note about 'int' rounding or truncating (python#102736)
  pythongh-102192: Replace PyErr_Fetch/Restore etc by more efficient alternatives (python#102760)
  pythongh-99726: Improves correctness of stat results for Windows, and uses faster API when available (pythonGH-102149)
  pythongh-102192: remove redundant exception fields from ssl module socket (python#102466)
  pythongh-102192: Replace PyErr_Fetch/Restore etc by more efficient alternatives (python#102743)
  pythongh-102737: Un-ignore ceval.c in the CI globals check (pythongh-102745)
  pythonGH-102748: remove legacy support for generator based coroutines from `asyncio.iscoroutine` (python#102749)
  pythongh-102721: Improve coverage of `_collections_abc._CallableGenericAlias` (python#102722)
  pythonGH-102653: Make recipe docstring show the correct distribution (python#102742)
  Add comments to `{typing,_collections_abc}._type_repr` about each other (python#102752)
  pythongh-102594: PyErr_SetObject adds note to exception raised on normalization error (python#102675)
  pythongh-94440: Fix issue of ProcessPoolExecutor shutdown hanging (python#94468)
  pythonGH-100112:  avoid using iterable coroutines in asyncio internally (python#100128)
  pythongh-102690: Use Edge as fallback in webbrowser instead of IE (python#102691)
  pythongh-102660: Fix Refleaks in import.c (python#102744)
  pythongh-102738: remove from cases generator the code related to register instructions (python#102739)
  ...
Fidget-Spinner pushed a commit to Fidget-Spinner/cpython that referenced this pull request Mar 27, 2023
@mdickinson @Fidget-Spinner
Fix outdated note about 'int' rounding or truncating (