os module: reject bytes-like strings for paths, only accept the exact bytes type

[vstinner]

In Python 3.6, the support for "bytes-like" paths was deprecated (commit d73c318): see issue #70987 for the rationale.

I propose to remove the support for bytes-like paths in Python 3.12. The feature was deprecated in 6 Python releases (PEP 387 is respected). In practice, the two most common "bytes-like" types are: bytearray and memoryview.

• PR: gh-98393: Update test_os for bytes-like types #98487

[vstinner]

In Python 3.2, I removed support for bytearray in PyUnicode_FSConverter(): issue #52731, commit dcb2403.

commit dcb2403022520028a633143602359a30080ed257
Author: Victor Stinner <[email protected]>
Date:   Thu Apr 22 12:08:36 2010 +0000

    Issue #8485: PyUnicode_FSConverter() doesn't accept bytearray object anymore,
    you have to convert your bytearray filenames to bytes

It seems like support for bytes-like object was added again in Python 3.4 with commit a2ad5c3 (issue #60176):

+        if (PyObject_CheckBuffer(o))
+            bytes = PyBytes_FromObject(o);

Or maybe this change is unrelated, and Python 3.2 and 3.3 already accepted bytes-like types indirectly.

[vstinner]

I created PR #98394 to implement this change.

[vstinner]

It seems like support for bytes-like object was added again in Python 3.4 with commit a2ad5c3 (issue #60176):

Ah no, it was reintroduced in Python 3.3 with "the big path_converter changes": #70987 (comment)

[vstinner]

Fixed by db03c80 (with f3007ac cleanup).