[consider-math-not-float] Add a check for `float("inf")`, `float("nan")` and `float("typos")` #10621

Pierre-Sassoulas · 2025-10-06T11:12:12Z

Type of Changes

	Type
✓	✨ New feature

Description

float("nan") and float("inf") are slower than their counterpart math.inf and math.nan by a factor of 4 :

import math
import timeit

time_math_inf = timeit.timeit('math.nan', globals=globals(), number=10**8)
print(f'math.nan: {time_math_inf:.2f} seconds')

import timeit
time_inf_str = timeit.timeit('float("nan")', number=10**8)
print(f'float("nan"): {time_inf_str:.2f} seconds')

math.nan: 1.24 seconds
float("nan"): 5.15 seconds

But:

import timeit

time_math_inf = timeit.timeit('import math;math.nan', globals=globals(), number=10**8)
print(f'math.nan: {time_math_inf:.2f} seconds')

import timeit
time_inf_str = timeit.timeit('float("nan")', number=10**8)
print(f'float("nan"): {time_inf_str:.2f} seconds')

math.nan: 9.08 seconds
float("nan"): 5.33 seconds

They are also not well typed when using mypy, see discussion in ruff: astral-sh/ruff#15908

I chose the code style checker without thinking too much about it and because there was already an inference call on the name of a call here. I can move it to the refactoring checker considering the benefit ? (Did this at work in pair so at least someone else than me and 4 person thumbsupping in the ruff issue consider this worthwhile)

codecov · 2025-10-06T11:32:22Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.96%. Comparing base (a85bf0c) to head (3541b99).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #10621   +/-   ##
=======================================
  Coverage   95.95%   95.96%           
=======================================
  Files         176      176           
  Lines       19504    19517   +13     
=======================================
+ Hits        18716    18729   +13     
  Misses        788      788

Files with missing lines	Coverage Δ
pylint/extensions/code_style.py	`100.00% <100.00%> (ø)`

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

Co-authored-by: Morwenn <[email protected]>

jacobtylerwalls · 2025-10-06T20:37:17Z

Off by default? 🤔

Pierre-Sassoulas · 2025-10-07T06:43:55Z

Do you mean it should be disabled by default in extension or added in checkers instead of extension ? 😄

…o account

doc/user_guide/checkers/extensions.rst

Co-authored-by: Morwenn <[email protected]>

jacobtylerwalls · 2025-10-07T08:34:57Z

Ah, I didn't realize it was in an extensions. nice.

Pierre-Sassoulas · 2025-10-07T08:41:21Z

Yeah, originally it wasn't obvious it should be an extension but I suppose the microbenchmark is misleading in the ruff issue because it doesn't take the "import math" into account. I also changed the "use" to "consider" in the message name because of this. If mypy understand better float("inf") one day this is going to be a really situational warning.

doc/whatsnew/fragments/10621.new_check

github-actions · 2025-10-07T10:45:14Z

🤖 Effect of this PR on checked open source code: 🤖

Effect on home-assistant:
The following messages are now emitted:

consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/helpers/significant_change.py#L164
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/habitica/todo.py#L284
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/habitica/todo.py#L370
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/knx/schema.py#L89
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/knx/schema.py#L97
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/stream/worker.py#L49
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/home-assistant/core/blob/b9a1ab4a44c36f3cf2c2073ee8da715ecd1f04ef/homeassistant/components/stream/recorder.py#L79

Effect on music21:
The following messages are now emitted:

consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/duration.py#L3961
consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/duration.py#L3969
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/base.py#L2069
consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/base.py#L3770
consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/base.py#L3969
consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/base.py#L3979
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/midi/realtime.py#L107
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/midi/realtime.py#L139
consider-math-not-float:
Consider math.nan instead of float('nan')
https://github.com/cuthbertLab/music21/blob/cb1bdfeb5303c02a9c2dff1f3e5d9232806dfd96/music21/stream/base.py#L8622

Effect on django:
The following messages are now emitted:

consider-math-not-float:
Consider math.nan instead of float('NaN')
https://github.com/django/django/blob/6e3287408e128e03a6ec5d23c17cdc2eee8760c0/django/contrib/gis/geos/prototypes/io.py#L267
consider-math-not-float:
Consider math.nan instead of float('NaN')
https://github.com/django/django/blob/6e3287408e128e03a6ec5d23c17cdc2eee8760c0/django/contrib/gis/geos/prototypes/io.py#L267

Effect on sentry:
The following messages are now emitted:

consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/spans/buffer.py#L199
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/spans/buffer.py#L200
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/models/groupsnooze.py#L103
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/models/groupsnooze.py#L163
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/models/groupsnooze.py#L211
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/interfaces/stacktrace.py#L131
consider-math-not-float:
Consider -math.inf instead of float('-inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/interfaces/stacktrace.py#L133
consider-math-not-float:
Consider math.inf instead of float('inf')
https://github.com/getsentry/sentry/blob/006dead493dea4fb0fbfc1bcf262373c660ee70c/src/sentry/ratelimits/concurrent.py#L15

This comment was generated for commit 3541b99

This PR contains the following updates: | Package | Change | Age | Confidence | |---|---|---|---| | [pylint](https://github.com/pylint-dev/pylint) ([changelog](https://pylint.readthedocs.io/en/latest/whatsnew/3/)) | `<4.0.0,>=3.3.3` -> `<4.1.0,>=4.0.0` | [![age](https://developer.mend.io/api/mc/badges/age/pypi/pylint/4.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/pylint/3.3.9/4.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | --- ### Release Notes <details> <summary>pylint-dev/pylint (pylint)</summary> ### [`v4.0.0`](https://github.com/pylint-dev/pylint/releases/tag/v4.0.0) [Compare Source](pylint-dev/pylint@v3.3.9...v4.0.0) - Pylint now supports Python 3.14. - Pylint's inference engine (`astroid`) is now much more precise, understanding implicit booleanness and ternary expressions. (Thanks [@zenlyj](https://github.com/zenlyj)!) Consider this example: ```python class Result: errors: dict | None = None result = Result() if result.errors: result.errors[field_key] ### inference engine understands result.errors cannot be None ### pylint no longer raises unsubscriptable-object ``` The required `astroid` version is now 4.0.0. See the [astroid changelog](https://pylint.readthedocs.io/projects/astroid/en/latest/changelog.html#what-s-new-in-astroid-4-0-0) for additional fixes, features, and performance improvements applicable to pylint. - Handling of `invalid-name` at the module level was patchy. Now, module-level constants that are reassigned are treated as variables and checked against `--variable-rgx` rather than `--const-rgx`. Module-level lists, sets, and objects can pass against either regex. Here, `LIMIT` is reassigned, so pylint only uses `--variable-rgx`: ```python LIMIT = 500 # [invalid-name] if sometimes: LIMIT = 1 # [invalid-name] ``` If this is undesired, refactor using *exclusive* assignment so that it is evident that this assignment happens only once: ```python if sometimes: LIMIT = 1 else: LIMIT = 500 # exclusive assignment: uses const regex, no warning ``` Lists, sets, and objects still pass against either `const-rgx` or `variable-rgx` even if reassigned, but are no longer completely skipped: ```python MY_LIST = [] my_list = [] My_List = [] # [invalid-name] ``` Remember to adjust the [regexes](https://pylint.readthedocs.io/en/latest/user_guide/messages/convention/invalid-name.html) and [allow lists](https://pylint.readthedocs.io/en/latest/user_guide/configuration/all-options.html#good-names) to your liking. ## Breaking Changes - `invalid-name` now distinguishes module-level constants that are assigned only once from those that are reassigned and now applies `--variable-rgx` to the latter. Values other than literals (lists, sets, objects) can pass against either the constant or variable regexes (e.g. "LOGGER" or "logger" but not "LoGgEr"). Remember that `--good-names` or `--good-names-rgxs` can be provided to explicitly allow good names. Closes [#3585](pylint-dev/pylint#3585) - The unused `pylintrc` argument to `PyLinter.__init__()` is deprecated and will be removed. Refs [#6052](pylint-dev/pylint#6052) - Commented out code blocks such as `# bar() # TODO: remove dead code` will no longer emit `fixme`. Refs [#9255](pylint-dev/pylint#9255) - `pyreverse` `Run` was changed to no longer call `sys.exit()` in its `__init__`. You should now call `Run(args).run()` which will return the exit code instead. Having a class that always raised a `SystemExit` exception was considered a bug. Normal usage of pyreverse through the CLI will not be affected by this change. Refs [#9689](pylint-dev/pylint#9689) - The `suggestion-mode` option was removed, as pylint now always emits user-friendly hints instead of false-positive error messages. You should remove it from your conf if it's defined. Refs [#9962](pylint-dev/pylint#9962) - The `async.py` checker module has been renamed to `async_checker.py` since `async` is a Python keyword and cannot be imported directly. This allows for better testing and extensibility of the async checker functionality. Refs [#10071](pylint-dev/pylint#10071) - The message-id of `continue-in-finally` was changed from `E0116` to `W0136`. The warning is now emitted for every Python version since it will raise a syntax warning in Python 3.14. See [PEP 765 - Disallow return/break/continue that exit a finally block](https://peps.python.org/pep-0765/). Refs [#10480](pylint-dev/pylint#10480) - Removed support for `nmp.NaN` alias for `numpy.NaN` being recognized in ':ref:`nan-comparison`'. Use `np` or `numpy` instead. Refs [#10583](pylint-dev/pylint#10583) - Version requirement for `isort` has been bumped to >=5.0.0. The internal compatibility for older `isort` versions exposed via `pylint.utils.IsortDriver` has been removed. Refs [#10637](pylint-dev/pylint#10637) ## New Features - `comparison-of-constants` now uses the unicode from the ast instead of reformatting from the node's values preventing some bad formatting due to `utf-8` limitation. The message now uses `"` instead of `'` to better work with what the python ast returns. Refs [#8736](pylint-dev/pylint#8736) - Enhanced pyreverse to properly distinguish between UML relationship types (association, aggregation, composition) based on object ownership semantics. Type annotations without assignment are now treated as associations, parameter assignments as aggregations, and object instantiation as compositions. Closes [#9045](pylint-dev/pylint#9045) Closes [#9267](pylint-dev/pylint#9267) - The `fixme` check can now search through docstrings as well as comments, by using `check-fixme-in-docstring = true` in the `[tool.pylint.miscellaneous]` section. Closes [#9255](pylint-dev/pylint#9255) - The `use-implicit-booleaness-not-x` checks now distinguish between comparisons used in boolean contexts and those that are not, enabling them to provide more accurate refactoring suggestions. Closes [#9353](pylint-dev/pylint#9353) - The verbose option now outputs the filenames of the files that have been checked. Previously, it only included the number of checked and skipped files. Closes [#9357](pylint-dev/pylint#9357) - colorized reporter now colorizes messages/categories that have been configured as `fail-on` in red inverse. This makes it easier to quickly find the errors that are causing pylint CI job failures. Closes [#9898](pylint-dev/pylint#9898) - Enhanced support for [@property](https://github.com/property) decorator in pyreverse to correctly display return types of annotated properties when generating class diagrams. Closes [#10057](pylint-dev/pylint#10057) - Add --max-depth option to pyreverse to control diagram complexity. A depth of 0 shows only top-level packages, 1 shows one level of subpackages, etc. This helps manage visualization of large codebases by limiting the depth of displayed packages and classes. Refs [#10077](pylint-dev/pylint#10077) - Handle deferred evaluation of annotations in Python 3.14. Closes [#10149](pylint-dev/pylint#10149) - Enhanced pyreverse to properly detect aggregations for comprehensions (list, dict, set, generator). Closes [#10236](pylint-dev/pylint#10236) - `pyreverse`: add support for colorized output when using output format `mmd` (MermaidJS) and `html`. Closes [#10242](pylint-dev/pylint#10242) - pypy 3.11 is now officially supported. Refs [#10287](pylint-dev/pylint#10287) - Add support for Python 3.14. Refs [#10467](pylint-dev/pylint#10467) - Add naming styles for `ParamSpec` and `TypeVarTuple` that align with the `TypeVar` style. Refs [#10541](pylint-dev/pylint#10541) ## New Checks - Add `match-statements` checker and the following message: `bare-name-capture-pattern`. This will emit an error message when a name capture pattern is used in a match statement which would make the remaining patterns unreachable. This code is a SyntaxError at runtime. Closes [#7128](pylint-dev/pylint#7128) - Add new check `async-context-manager-with-regular-with` to detect async context managers used with regular `with` statements instead of `async with`. Refs [#10408](pylint-dev/pylint#10408) - Add `break-in-finally` warning. Using `break` inside the `finally` clause will raise a syntax warning in Python 3.14. See `PEP 765 - Disallow return/break/continue that exit a finally block <https://peps.python.org/pep-0765/>`\_. Refs [#10480](pylint-dev/pylint#10480) - Add new checks for invalid uses of class patterns in :keyword:`match`. - :ref:`invalid-match-args-definition` is emitted if :py:data:`object.__match_args__` isn't a tuple of strings. - :ref:`too-many-positional-sub-patterns` if there are more positional sub-patterns than specified in :py:data:`object.__match_args__`. - :ref:`multiple-class-sub-patterns` if there are multiple sub-patterns for the same attribute. Refs [#10559](pylint-dev/pylint#10559) - Add additional checks for suboptimal uses of class patterns in :keyword:`match`. - :ref:`match-class-bind-self` is emitted if a name is bound to `self` instead of using an `as` pattern. - :ref:`match-class-positional-attributes` is emitted if a class pattern has positional attributes when keywords could be used. Refs [#10587](pylint-dev/pylint#10587) - Add a `consider-math-not-float` message. `float("nan")` and `float("inf")` are slower than their counterpart `math.inf` and `math.nan` by a factor of 4 (notwithstanding the initial import of math) and they are also not well typed when using mypy. This check also catches typos in float calls as a side effect. The :ref:`pylint.extensions.code_style` need to be activated for this check to work. Refs [#10621](pylint-dev/pylint#10621) ## False Positives Fixed - Fix a false positive for `used-before-assignment` when a variable defined under an `if` and via a named expression (walrus operator) is used later when guarded under the same `if` test. Closes [#10061](pylint-dev/pylint#10061) - Fix :ref:`no-name-in-module` for members of `concurrent.futures` with Python 3.14. Closes [#10632](pylint-dev/pylint#10632) ## False Negatives Fixed - Fix false negative for `used-before-assignment` when a `TYPE_CHECKING` import is used as a type annotation prior to erroneous usage. Refs [#8893](pylint-dev/pylint#8893) - Match cases are now counted as edges in the McCabe graph and will increase the complexity accordingly. Refs [#9667](pylint-dev/pylint#9667) - Check module-level constants with type annotations for `invalid-name`. Remember to adjust `const-naming-style` or `const-rgx` to your liking. Closes [#9770](pylint-dev/pylint#9770) - Fix false negative where function-redefined (E0102) was not reported for functions with a leading underscore. Closes [#9894](pylint-dev/pylint#9894) - We now raise a `logging-too-few-args` for format string with no interpolation arguments at all (i.e. for something like `logging.debug("Awaiting process %s")` or `logging.debug("Awaiting process {pid}")`). Previously we did not raise for such case. Closes [#9999](pylint-dev/pylint#9999) - Fix false negative for `used-before-assignment` when a function is defined inside a `TYPE_CHECKING` guard block and used later. Closes [#10028](pylint-dev/pylint#10028) - Fix a false negative for `possibly-used-before-assignment` when a variable is conditionally defined and later assigned to a type-annotated variable. Closes [#10421](pylint-dev/pylint#10421) - Fix false negative for `deprecated-module` when a `__import__` method is used instead of `import` sentence. Refs [#10453](pylint-dev/pylint#10453) - Count match cases for `too-many-branches` check. Refs [#10542](pylint-dev/pylint#10542) - Fix false-negative where :ref:`unused-import` was not reported for names referenced in a preceding `global` statement. Refs [#10633](pylint-dev/pylint#10633) ## Other Bug Fixes - When displaying unicode with surrogates (or other potential `UnicodeEncodeError`), pylint will now display a '?' character (using `encode(encoding="utf-8", errors="replace")`) instead of crashing. The functional tests classes are also updated to handle this case. Closes [#8736](pylint-dev/pylint#8736) - Fixed unidiomatic-typecheck only checking left-hand side. Closes [#10217](pylint-dev/pylint#10217) - Fix a crash caused by malformed format strings when using `.format` with keyword arguments. Closes [#10282](pylint-dev/pylint#10282) - Fix false positive `inconsistent-return-statements` when using `quit()` or `exit()` functions. Closes [#10508](pylint-dev/pylint#10508) - Fix a crash in :ref:`nested-min-max` when using `builtins.min` or `builtins.max` instead of `min` or `max` directly. Closes [#10626](pylint-dev/pylint#10626) - Fixed a crash in :ref:`unnecessary-dict-index-lookup` when the index of an enumerated list was deleted inside a for loop. Closes [#10627](pylint-dev/pylint#10627) ## Other Changes - Remove support for launching pylint with Python 3.9. Code that supports Python 3.9 can still be linted with the `--py-version=3.9` setting. Refs [#10405](pylint-dev/pylint#10405) ## Internal Changes - Modified test framework to allow for different test output for different Python versions. Refs [#10382](pylint-dev/pylint#10382) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/roboluke/pulls/384 Co-authored-by: renovate[bot] <[email protected]> Co-committed-by: renovate[bot] <[email protected]>

This PR contains the following updates: | Package | Change | Age | Confidence | |---|---|---|---| | [pylint](https://github.com/pylint-dev/pylint) ([changelog](https://pylint.readthedocs.io/en/latest/whatsnew/3/)) | `<4.0.0,>=3.3.3` -> `<4.1.0,>=4.0.0` | [![age](https://developer.mend.io/api/mc/badges/age/pypi/pylint/4.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/pylint/3.3.9/4.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | --- ### Release Notes <details> <summary>pylint-dev/pylint (pylint)</summary> ### [`v4.0.0`](https://github.com/pylint-dev/pylint/releases/tag/v4.0.0) [Compare Source](pylint-dev/pylint@v3.3.9...v4.0.0) - Pylint now supports Python 3.14. - Pylint's inference engine (`astroid`) is now much more precise, understanding implicit booleanness and ternary expressions. (Thanks [@zenlyj](https://github.com/zenlyj)!) Consider this example: ```python class Result: errors: dict | None = None result = Result() if result.errors: result.errors[field_key] ### inference engine understands result.errors cannot be None ### pylint no longer raises unsubscriptable-object ``` The required `astroid` version is now 4.0.0. See the [astroid changelog](https://pylint.readthedocs.io/projects/astroid/en/latest/changelog.html#what-s-new-in-astroid-4-0-0) for additional fixes, features, and performance improvements applicable to pylint. - Handling of `invalid-name` at the module level was patchy. Now, module-level constants that are reassigned are treated as variables and checked against `--variable-rgx` rather than `--const-rgx`. Module-level lists, sets, and objects can pass against either regex. Here, `LIMIT` is reassigned, so pylint only uses `--variable-rgx`: ```python LIMIT = 500 # [invalid-name] if sometimes: LIMIT = 1 # [invalid-name] ``` If this is undesired, refactor using *exclusive* assignment so that it is evident that this assignment happens only once: ```python if sometimes: LIMIT = 1 else: LIMIT = 500 # exclusive assignment: uses const regex, no warning ``` Lists, sets, and objects still pass against either `const-rgx` or `variable-rgx` even if reassigned, but are no longer completely skipped: ```python MY_LIST = [] my_list = [] My_List = [] # [invalid-name] ``` Remember to adjust the [regexes](https://pylint.readthedocs.io/en/latest/user_guide/messages/convention/invalid-name.html) and [allow lists](https://pylint.readthedocs.io/en/latest/user_guide/configuration/all-options.html#good-names) to your liking. ## Breaking Changes - `invalid-name` now distinguishes module-level constants that are assigned only once from those that are reassigned and now applies `--variable-rgx` to the latter. Values other than literals (lists, sets, objects) can pass against either the constant or variable regexes (e.g. "LOGGER" or "logger" but not "LoGgEr"). Remember that `--good-names` or `--good-names-rgxs` can be provided to explicitly allow good names. Closes [#3585](pylint-dev/pylint#3585) - The unused `pylintrc` argument to `PyLinter.__init__()` is deprecated and will be removed. Refs [#6052](pylint-dev/pylint#6052) - Commented out code blocks such as `# bar() # TODO: remove dead code` will no longer emit `fixme`. Refs [#9255](pylint-dev/pylint#9255) - `pyreverse` `Run` was changed to no longer call `sys.exit()` in its `__init__`. You should now call `Run(args).run()` which will return the exit code instead. Having a class that always raised a `SystemExit` exception was considered a bug. Normal usage of pyreverse through the CLI will not be affected by this change. Refs [#9689](pylint-dev/pylint#9689) - The `suggestion-mode` option was removed, as pylint now always emits user-friendly hints instead of false-positive error messages. You should remove it from your conf if it's defined. Refs [#9962](pylint-dev/pylint#9962) - The `async.py` checker module has been renamed to `async_checker.py` since `async` is a Python keyword and cannot be imported directly. This allows for better testing and extensibility of the async checker functionality. Refs [#10071](pylint-dev/pylint#10071) - The message-id of `continue-in-finally` was changed from `E0116` to `W0136`. The warning is now emitted for every Python version since it will raise a syntax warning in Python 3.14. See [PEP 765 - Disallow return/break/continue that exit a finally block](https://peps.python.org/pep-0765/). Refs [#10480](pylint-dev/pylint#10480) - Removed support for `nmp.NaN` alias for `numpy.NaN` being recognized in ':ref:`nan-comparison`'. Use `np` or `numpy` instead. Refs [#10583](pylint-dev/pylint#10583) - Version requirement for `isort` has been bumped to >=5.0.0. The internal compatibility for older `isort` versions exposed via `pylint.utils.IsortDriver` has been removed. Refs [#10637](pylint-dev/pylint#10637) ## New Features - `comparison-of-constants` now uses the unicode from the ast instead of reformatting from the node's values preventing some bad formatting due to `utf-8` limitation. The message now uses `"` instead of `'` to better work with what the python ast returns. Refs [#8736](pylint-dev/pylint#8736) - Enhanced pyreverse to properly distinguish between UML relationship types (association, aggregation, composition) based on object ownership semantics. Type annotations without assignment are now treated as associations, parameter assignments as aggregations, and object instantiation as compositions. Closes [#9045](pylint-dev/pylint#9045) Closes [#9267](pylint-dev/pylint#9267) - The `fixme` check can now search through docstrings as well as comments, by using `check-fixme-in-docstring = true` in the `[tool.pylint.miscellaneous]` section. Closes [#9255](pylint-dev/pylint#9255) - The `use-implicit-booleaness-not-x` checks now distinguish between comparisons used in boolean contexts and those that are not, enabling them to provide more accurate refactoring suggestions. Closes [#9353](pylint-dev/pylint#9353) - The verbose option now outputs the filenames of the files that have been checked. Previously, it only included the number of checked and skipped files. Closes [#9357](pylint-dev/pylint#9357) - colorized reporter now colorizes messages/categories that have been configured as `fail-on` in red inverse. This makes it easier to quickly find the errors that are causing pylint CI job failures. Closes [#9898](pylint-dev/pylint#9898) - Enhanced support for [@property](https://github.com/property) decorator in pyreverse to correctly display return types of annotated properties when generating class diagrams. Closes [#10057](pylint-dev/pylint#10057) - Add --max-depth option to pyreverse to control diagram complexity. A depth of 0 shows only top-level packages, 1 shows one level of subpackages, etc. This helps manage visualization of large codebases by limiting the depth of displayed packages and classes. Refs [#10077](pylint-dev/pylint#10077) - Handle deferred evaluation of annotations in Python 3.14. Closes [#10149](pylint-dev/pylint#10149) - Enhanced pyreverse to properly detect aggregations for comprehensions (list, dict, set, generator). Closes [#10236](pylint-dev/pylint#10236) - `pyreverse`: add support for colorized output when using output format `mmd` (MermaidJS) and `html`. Closes [#10242](pylint-dev/pylint#10242) - pypy 3.11 is now officially supported. Refs [#10287](pylint-dev/pylint#10287) - Add support for Python 3.14. Refs [#10467](pylint-dev/pylint#10467) - Add naming styles for `ParamSpec` and `TypeVarTuple` that align with the `TypeVar` style. Refs [#10541](pylint-dev/pylint#10541) ## New Checks - Add `match-statements` checker and the following message: `bare-name-capture-pattern`. This will emit an error message when a name capture pattern is used in a match statement which would make the remaining patterns unreachable. This code is a SyntaxError at runtime. Closes [#7128](pylint-dev/pylint#7128) - Add new check `async-context-manager-with-regular-with` to detect async context managers used with regular `with` statements instead of `async with`. Refs [#10408](pylint-dev/pylint#10408) - Add `break-in-finally` warning. Using `break` inside the `finally` clause will raise a syntax warning in Python 3.14. See `PEP 765 - Disallow return/break/continue that exit a finally block <https://peps.python.org/pep-0765/>`\_. Refs [#10480](pylint-dev/pylint#10480) - Add new checks for invalid uses of class patterns in :keyword:`match`. - :ref:`invalid-match-args-definition` is emitted if :py:data:`object.__match_args__` isn't a tuple of strings. - :ref:`too-many-positional-sub-patterns` if there are more positional sub-patterns than specified in :py:data:`object.__match_args__`. - :ref:`multiple-class-sub-patterns` if there are multiple sub-patterns for the same attribute. Refs [#10559](pylint-dev/pylint#10559) - Add additional checks for suboptimal uses of class patterns in :keyword:`match`. - :ref:`match-class-bind-self` is emitted if a name is bound to `self` instead of using an `as` pattern. - :ref:`match-class-positional-attributes` is emitted if a class pattern has positional attributes when keywords could be used. Refs [#10587](pylint-dev/pylint#10587) - Add a `consider-math-not-float` message. `float("nan")` and `float("inf")` are slower than their counterpart `math.inf` and `math.nan` by a factor of 4 (notwithstanding the initial import of math) and they are also not well typed when using mypy. This check also catches typos in float calls as a side effect. The :ref:`pylint.extensions.code_style` need to be activated for this check to work. Refs [#10621](pylint-dev/pylint#10621) ## False Positives Fixed - Fix a false positive for `used-before-assignment` when a variable defined under an `if` and via a named expression (walrus operator) is used later when guarded under the same `if` test. Closes [#10061](pylint-dev/pylint#10061) - Fix :ref:`no-name-in-module` for members of `concurrent.futures` with Python 3.14. Closes [#10632](pylint-dev/pylint#10632) ## False Negatives Fixed - Fix false negative for `used-before-assignment` when a `TYPE_CHECKING` import is used as a type annotation prior to erroneous usage. Refs [#8893](pylint-dev/pylint#8893) - Match cases are now counted as edges in the McCabe graph and will increase the complexity accordingly. Refs [#9667](pylint-dev/pylint#9667) - Check module-level constants with type annotations for `invalid-name`. Remember to adjust `const-naming-style` or `const-rgx` to your liking. Closes [#9770](pylint-dev/pylint#9770) - Fix false negative where function-redefined (E0102) was not reported for functions with a leading underscore. Closes [#9894](pylint-dev/pylint#9894) - We now raise a `logging-too-few-args` for format string with no interpolation arguments at all (i.e. for something like `logging.debug("Awaiting process %s")` or `logging.debug("Awaiting process {pid}")`). Previously we did not raise for such case. Closes [#9999](pylint-dev/pylint#9999) - Fix false negative for `used-before-assignment` when a function is defined inside a `TYPE_CHECKING` guard block and used later. Closes [#10028](pylint-dev/pylint#10028) - Fix a false negative for `possibly-used-before-assignment` when a variable is conditionally defined and later assigned to a type-annotated variable. Closes [#10421](pylint-dev/pylint#10421) - Fix false negative for `deprecated-module` when a `__import__` method is used instead of `import` sentence. Refs [#10453](pylint-dev/pylint#10453) - Count match cases for `too-many-branches` check. Refs [#10542](pylint-dev/pylint#10542) - Fix false-negative where :ref:`unused-import` was not reported for names referenced in a preceding `global` statement. Refs [#10633](pylint-dev/pylint#10633) ## Other Bug Fixes - When displaying unicode with surrogates (or other potential `UnicodeEncodeError`), pylint will now display a '?' character (using `encode(encoding="utf-8", errors="replace")`) instead of crashing. The functional tests classes are also updated to handle this case. Closes [#8736](pylint-dev/pylint#8736) - Fixed unidiomatic-typecheck only checking left-hand side. Closes [#10217](pylint-dev/pylint#10217) - Fix a crash caused by malformed format strings when using `.format` with keyword arguments. Closes [#10282](pylint-dev/pylint#10282) - Fix false positive `inconsistent-return-statements` when using `quit()` or `exit()` functions. Closes [#10508](pylint-dev/pylint#10508) - Fix a crash in :ref:`nested-min-max` when using `builtins.min` or `builtins.max` instead of `min` or `max` directly. Closes [#10626](pylint-dev/pylint#10626) - Fixed a crash in :ref:`unnecessary-dict-index-lookup` when the index of an enumerated list was deleted inside a for loop. Closes [#10627](pylint-dev/pylint#10627) ## Other Changes - Remove support for launching pylint with Python 3.9. Code that supports Python 3.9 can still be linted with the `--py-version=3.9` setting. Refs [#10405](pylint-dev/pylint#10405) ## Internal Changes - Modified test framework to allow for different test output for different Python versions. Refs [#10382](pylint-dev/pylint#10382) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/epage/pulls/168 Co-authored-by: renovate[bot] <[email protected]> Co-committed-by: renovate[bot] <[email protected]>

Pierre-Sassoulas requested a review from cdce8p as a code owner October 6, 2025 11:12

Pierre-Sassoulas added the Enhancement ✨ Improvement to a component label Oct 6, 2025

Pierre-Sassoulas force-pushed the use-math-not-float branch from 341d145 to b127d04 Compare October 6, 2025 11:19

This comment has been minimized.

Sign in to view

Pierre-Sassoulas force-pushed the use-math-not-float branch from b127d04 to fe7f298 Compare October 6, 2025 12:15

Pierre-Sassoulas added the Needs review 🔍 Needs to be reviewed by one or multiple more persons label Oct 6, 2025

This comment has been minimized.

Sign in to view

Pierre-Sassoulas requested review from jacobtylerwalls and removed request for cdce8p October 6, 2025 18:47

Pierre-Sassoulas and others added 3 commits October 6, 2025 21:36

[use-math-not-float] Add a check for float(inf) and float(nan)

902096c

Co-authored-by: Morwenn <[email protected]>

Take into account the limitation of the microbenchmark

4fa1375

Handle typo in float call more gracefully

bda3d30

Pierre-Sassoulas force-pushed the use-math-not-float branch from d767cb7 to bda3d30 Compare October 6, 2025 19:36

This comment has been minimized.

Sign in to view

Make the message less prescriptive as the import need to be taken int…

d25b7fb

…o account

Pierre-Sassoulas force-pushed the use-math-not-float branch from be11be6 to d25b7fb Compare October 7, 2025 07:47

Pierre-Sassoulas changed the title ~~[use-math-not-float] Add a check for float(inf) and float(nan)~~ [use-math-not-float] Add a check for float("inf"), float("nan") and float("typos") Oct 7, 2025

Morwenn reviewed Oct 7, 2025

View reviewed changes

doc/user_guide/checkers/extensions.rst Outdated Show resolved Hide resolved

This comment has been minimized.

Sign in to view

Update doc/user_guide/checkers/extensions.rst

2cd4cda

Co-authored-by: Morwenn <[email protected]>

Upgrade doc / code following typos fix

38914db

Pierre-Sassoulas changed the title ~~[use-math-not-float] Add a check for float("inf"), float("nan") and float("typos")~~ [consider-math-not-float] Add a check for float("inf"), float("nan") and float("typos") Oct 7, 2025

Pierre-Sassoulas commented Oct 7, 2025

View reviewed changes

doc/whatsnew/fragments/10621.new_check Show resolved Hide resolved

This comment has been minimized.

Sign in to view

Update doc/whatsnew/fragments/10621.new_check

3541b99

Pierre-Sassoulas requested a review from DanielNoord October 7, 2025 10:19

DanielNoord approved these changes Oct 7, 2025

View reviewed changes

Pierre-Sassoulas merged commit a0bfd3f into main Oct 8, 2025
44 checks passed

Pierre-Sassoulas deleted the use-math-not-float branch October 8, 2025 06:12

Pierre-Sassoulas temporarily deployed to Backport October 8, 2025 06:12 — with GitHub Actions Inactive

Pierre-Sassoulas removed the Needs review 🔍 Needs to be reviewed by one or multiple more persons label Oct 8, 2025

Pierre-Sassoulas added this to the 4.0.0 milestone Oct 8, 2025

Pierre-Sassoulas mentioned this pull request Oct 12, 2025

Release branch for 4.0.0 #10639

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

[consider-math-not-float] Add a check for `float("inf")`, `float("nan")` and `float("typos")` #10621

[consider-math-not-float] Add a check for `float("inf")`, `float("nan")` and `float("typos")` #10621

Uh oh!

Pierre-Sassoulas commented Oct 6, 2025 •

edited

Loading

Uh oh!

codecov bot commented Oct 6, 2025 •

edited

Loading

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

jacobtylerwalls commented Oct 6, 2025

Uh oh!

Pierre-Sassoulas commented Oct 7, 2025

Uh oh!

Uh oh!

This comment has been minimized.

jacobtylerwalls commented Oct 7, 2025

Uh oh!

Pierre-Sassoulas commented Oct 7, 2025

Uh oh!

Uh oh!

This comment has been minimized.

github-actions bot commented Oct 7, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Uh oh!

[consider-math-not-float] Add a check for float("inf"), float("nan") and float("typos") #10621

[consider-math-not-float] Add a check for float("inf"), float("nan") and float("typos") #10621

Uh oh!

Conversation

Pierre-Sassoulas commented Oct 6, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Type of Changes

Description

Uh oh!

codecov bot commented Oct 6, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

jacobtylerwalls commented Oct 6, 2025

Uh oh!

Pierre-Sassoulas commented Oct 7, 2025

Uh oh!

Uh oh!

This comment has been minimized.

jacobtylerwalls commented Oct 7, 2025

Uh oh!

Pierre-Sassoulas commented Oct 7, 2025

Uh oh!

Uh oh!

This comment has been minimized.

github-actions bot commented Oct 7, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

[consider-math-not-float] Add a check for `float("inf")`, `float("nan")` and `float("typos")` #10621

[consider-math-not-float] Add a check for `float("inf")`, `float("nan")` and `float("typos")` #10621

Pierre-Sassoulas commented Oct 6, 2025 •

edited

Loading

codecov bot commented Oct 6, 2025 •

edited

Loading