Add option for redirecting stdout and stderr to the system log

Feature or enhancement

Proposal:

Python currently assumes that stdout and stderr are streams that are universally available. This is true for most systems.
However, on iOS, stdout/stderr content is only really visible while in Xcode. When an app is running in the wild, the expectation is that the app will use the system log for all output needs.

On iOS, stdout and stderr should be automatically directed to the system log (with appropriate log levels). This matches what Android does by default (see #118063). Existing iOS apps in the wild need to use a shim such as std-nslog to ensure that stdout/err content can be loaded at runtime. This also complicates the iOS testing story, as stdout/stderr content is only visible at the end of a test run, rather than being streamable content as the test runs.

As iOS and macOS share an underlying logging framework, it should also be possible to have this functionality on macOS as well (on an opt-in basis when the Python interpreter is configured). This would be useful for Python code that has been embedded into a native macOS GUI app. At present, stdout and stderr are essentially inaccessible for apps of this type.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

Addressing this is likely a pre-requisite for addressing #126925.

The PR linked to the issue is still open. Either the PR should be closed or merged, or the issue re-opened.

@terryjreedy

@terryjreedy The feature was implemented in #127592; the linked open PR is a documentation update that is specific to this feature that is waiting on a review.

If it still needed review, I would re-open. But since I think it ready to merge, not.

gh-126821: Add versionadded annotation to use_system_logger feature. (#…

pythongh-126821: Add versionadded annotation to use_system_logger fea…

[3.13] gh-126821: Add versionadded annotation to use_system_logger fe…

[3.9] pythongh-126821: Add versionadded annotation to use_system_logg…

[3.10] pythongh-126821: Add versionadded annotation to use_system_log…

[3.12] pythongh-126821: Add versionadded annotation to use_system_log…

[3.13] pythongh-126821: Add versionadded annotation to use_system_log…

pythongh-126821: Add versionadded annotation to use_system_logger fea…

[3.11] pythongh-126821: Add versionadded annotation to use_system_log…