added exception groups

[iritkatriel]

First step of PEP-654: added Exception Groups (without updating traceback formatting).

[iritkatriel]

Unfortunately we can't express here that ExceptionGroup subclasses BaseExceptionGroup as well.

[gvanrossum]

Add a note in parentheses?

[iritkatriel]

There seems to be an unused feature that interprets whatever is in "(..)" as a platform name and then ignores any exception where the platform is not the current platform (so it won't break the test but will weaken it).

But "[...]" seems ok - anything in them appears to be ignored, and when I changed ExceptionGroup to something invalid the test failed.

cpython/Lib/test/test_baseexception.py

Line 49 in 8bbfeb3

if '(' in exc_name:

[gvanrossum]

Is this what we will merge once the PEP is accepted?

(Note that the master -> main rename will happen at that time too. But supposedly PSs will be automatically adjusted. We’ll see.)

[gvanrossum]

Add a note in parentheses?

[gvanrossum]

Probably mark as Draft?

[iritkatriel]

Is this what we will merge once the PEP is accepted?

That's the idea. The branch of the other PR is very old and compile.c/eval.c changed beyond what can be fixed with a rebase. So I started from scratch on a recent cut of master. Marked as draft for now.

[iritkatriel]

There seems to be an unused feature that interprets whatever is in "(..)" as a platform name and then ignores any exception where the platform is not the current platform (so it won't break the test but will weaken it).

But "[...]" seems ok - anything in them appears to be ignored, and when I changed ExceptionGroup to something invalid the test failed.

cpython/Lib/test/test_baseexception.py

Line 49 in 8bbfeb3

if '(' in exc_name:

[gvanrossum]

You should probably merge this on main.

[iritkatriel]

I rebased and regenerated Python/importlib_external.h

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[iritkatriel]

Superseded by #28569.