Bug report

Bug description:

import sys
sys.implementation.supports_isolated_interpreters

This is missing, but the accepted PEP 734 says this is provided so implementations can avoid supporting isolated interpreters (GraalPy, for example, does not yet). Was it overlooked, perhaps?

I was using it like this with 3.14.0b3:

    if (
        sys.version_info >= (3, 14)
        and (
            sys.version_info != (3, 14, 0, "beta", 1)
            or sys.version_info != (3, 14, 0, "beta", 2)
        )
        and sys.implementation.supports_isolated_interpreters
    ):
        from concurrent import interpreters

CC @ericsnowcurrently

CPython versions tested on:

3.14

Operating systems tested on:

macOS

Linked PRs

gh-135645: Added supports_isolated_interpreters to sys.implementation #135667
[3.14] gh-135645: Added supports_isolated_interpreters to sys.implementation (GH-135667) #135786