Fix typings of `ExceptionGroup` and `BaseExceptionGroup` by sobolevn · Pull Request #9230 · python/typeshed · GitHub

There are a lot of things going on in this PR:

Methods no longer return Self type, because of how C implementation works
split and subgroup require Self argument to be in callable, because of how C implementation works
Some casts from BaseExceptionGroup to and from ExceptionGroup are supported. But not all of them

This is a very complex PR. I would love to provide any of my help to the reviewers.

Ok, pyright has only 10 problems:

/home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:28:13 - error: "assert_type" mismatch: expected "BaseExceptionGroup[BaseException] | None" but received "BaseExceptionGroup[KeyboardInterrupt | SystemExit] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:57:13 - error: "assert_type" mismatch: expected "ExceptionGroup[Exception] | None" but received "ExceptionGroup[ValueError | KeyError] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:88:5 - error: "assert_type" mismatch: expected "tuple[BaseExceptionGroup[BaseException] | None, BaseExceptionGroup[SystemExit] | None]" but received "tuple[BaseExceptionGroup[KeyboardInterrupt | SystemExit] | None, BaseExceptionGroup[SystemExit] | None]" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:173:13 - error: "assert_type" mismatch: expected "ExceptionGroup[Exception] | None" but received "ExceptionGroup[ValueError | KeyError] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:198:5 - error: "assert_type" mismatch: expected "tuple[ExceptionGroup[Exception] | None, ExceptionGroup[ValueError | KeyError] | None]" but received "tuple[ExceptionGroup[TypeError | IndexError] | None, ExceptionGroup[ValueError | KeyError] | None]" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:252:13 - error: "assert_type" mismatch: expected "BaseExceptionGroup[BaseException] | None" but received "BaseExceptionGroup[KeyboardInterrupt | SystemExit] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:255:13 - error: "assert_type" mismatch: expected "ExceptionGroup[Exception] | None" but received "ExceptionGroup[KeyError | TypeError] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:279:13 - error: "assert_type" mismatch: expected "tuple[ExceptionGroup[Exception] | None, BaseExceptionGroup[ValueError] | None]" but received "tuple[ExceptionGroup[TypeError | IndexError] | None, BaseExceptionGroup[ValueError] | None]" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:328:13 - error: "assert_type" mismatch: expected "ExceptionGroup[Exception] | None" but received "ExceptionGroup[KeyError | TypeError] | None" (reportGeneralTypeIssues)
  /home/runner/work/typeshed/typeshed/test_cases/stdlib/builtins/check_exception_group.py:347:13 - error: "assert_type" mismatch: expected "tuple[ExceptionGroup[Exception] | None, ExceptionGroup[ValueError] | None]" but received "tuple[ExceptionGroup[TypeError | IndexError] | None, ExceptionGroup[ValueError] | None]" (reportGeneralTypeIssues)
10 errors, 0 warnings, 0 informations

I will add a version guard later on.

Looks like we need some other solution for unused # type: ignore comments.

 Running mypy --platform darwin --python-version 3.11 on the test cases for 'invoke'... success
Running mypy --platform darwin --python-version 3.11 on the test cases for 'requests'... success
Running mypy --platform darwin --python-version 3.11 on the standard library test cases... success
Running mypy --platform darwin --python-version 3.10 on the test cases for 'invoke'... success
Running mypy --platform darwin --python-version 3.10 on the test cases for 'requests'... success
Running mypy --platform darwin --python-version 3.10 on the standard library test cases... failure

test_cases/stdlib/builtins/check_exception_group.py:47: error: Unused "type: ignore" comment
test_cases/stdlib/builtins/check_exception_group.py:48: error: Unused "type: ignore" comment
test_cases/stdlib/builtins/check_exception_group.py:67: error: Unused "type: ignore" comment
test_cases/stdlib/builtins/check_exception_group.py:71: error: Unused "type: ignore" comment
...

Should be doable by overriding __new__ (python/mypy#7188), did you try that?

We have three cases:

BaseExceptionGroup.__new__ can return BaseExceptionGroup for _BaseExceptionT_co
BaseExceptionGroup.__new__ can return ExceptionGroup for _ExceptionT_co
BaseExceptionGroup.__new__ can return custom subclass

Either the first two work or the third one. Suggestions are welcome

I have an idea for how to fix the test cases on mypy; I'll get to work on a fix.

For flake8: would an alternative fix be to have from builtins import BaseExceptionGroup, ExceptionGroup at the top of the file?

@AlexWaygood, thank you, flake8 idea worked!

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

Hooray, CI is finally green 🎉

I really hope this is correct now! Ping me in case of any problems.

sobolevn and others added 2 commits November 20, 2022 17:05

Fix typings of ExceptionGroup and BaseExceptionGroup

3412cdd

[pre-commit.ci] auto fixes from pre-commit.com hooks

d6090ed

This comment has been minimized.

Sign in to view

JelleZijlstra and others added 2 commits November 20, 2022 06:29

only in 3.11

4e37a93

[pre-commit.ci] auto fixes from pre-commit.com hooks

5daa26c

This comment has been minimized.

Sign in to view

JelleZijlstra reviewed Nov 20, 2022

View reviewed changes

sobolevn and others added 4 commits November 21, 2022 16:32

Address review

9c06c0a

Fix pyright

0eaf7b8

[pre-commit.ci] auto fixes from pre-commit.com hooks

7e57c9c

Fix flake8

aba41b9

This comment has been minimized.

Sign in to view

Fix flake8

7416e6a

[pre-commit.ci] auto fixes from pre-commit.com hooks

caccf63

This comment has been minimized.

Sign in to view

AlexWaygood mentioned this pull request Nov 21, 2022

Allow adding test cases testing version-dependent Python features #9238

Merged

AlexWaygood added 2 commits November 21, 2022 16:58

Merge remote-tracking branch 'upstream/main' into issue-9219

7c6735b

Add the magic suffix to the test-case filename

93a4638

This comment has been minimized.

Sign in to view

AlexWaygood mentioned this pull request Nov 21, 2022

check_consistent.py: Allow having weird filenames in the test_cases directory #9239

Merged

Merge branch 'main' into issue-9219

8828619

JelleZijlstra merged commit ae58142 into python:main Nov 23, 2022

AlexWaygood mentioned this pull request Nov 23, 2022

Return types for (Base)ExceptionGroup.derive(), .subgroup(), and .split() should not use Self #9219

Closed

jakkdl mentioned this pull request Aug 6, 2023

Add types to _core._run python-trio/trio#2733

Merged

A5rocks mentioned this pull request Aug 10, 2023

misclick python-trio/trio#2748

Closed

jakkdl mentioned this pull request Jan 28, 2025

BaseExceptionGroup should return ExceptionGroup if initialized with non-base exceptions #12972

Open

+                  # `BaseExceptionGroup` can work with `Exception`:
+                  beg2 = BaseExceptionGroup("x", [ValueError()])
+                  # FIXME: this is not right, runtime returns `ExceptionGroup` instance instead,

Fix typings of `ExceptionGroup` and `BaseExceptionGroup` by sobolevn · Pull Request #9230 · python/typeshed · GitHub

Repository navigation

Fix typings of ExceptionGroup and BaseExceptionGroup - #9230

Fix typings of ExceptionGroup and BaseExceptionGroup#9230JelleZijlstra merged 13 commits intopython:mainpython/typeshed:mainfrom sobolevn:issue-9219sobolevn/typeshed:issue-9219Copy head branch name to clipboard

Conversation

sobolevn commented Nov 20, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

sobolevn commented Nov 20, 2022

Uh oh!

This comment has been minimized.

sobolevn commented Nov 20, 2022

Uh oh!

This comment has been minimized.

Uh oh!

JelleZijlstra Nov 20, 2022

Choose a reason for hiding this comment

Uh oh!

sobolevn Nov 21, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

AlexWaygood commented Nov 21, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

This comment has been minimized.

sobolevn commented Nov 21, 2022

Uh oh!

This comment has been minimized.

This comment has been minimized.

github-actions Bot commented Nov 21, 2022

Uh oh!

AlexWaygood commented Nov 21, 2022

Uh oh!

sobolevn commented Nov 23, 2022

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Fix typings of ExceptionGroup and BaseExceptionGroup#9230
JelleZijlstra merged 13 commits into
python:mainfrom
sobolevn:issue-9219

sobolevn commented Nov 20, 2022 •
edited
Loading

sobolevn Nov 21, 2022 •
edited
Loading

AlexWaygood commented Nov 21, 2022 •
edited
Loading