`struct.pack` with format `s` errors on `bytes`-like data

Bug report

Bug description:

When using struct.pack with format s, it works with bytes and bytearray. However other bytes-like data (such as memoryview) is not handled raising an error. Here is some sample code show this issue

import struct

b = b"abad"

struct. pack("4s", b)               # Ok
struct. pack("4s", bytearray(b))    # Ok
struct. pack("4s", memoryview(b))   # Error

This code appears to contain the corresponding logic

https://github.com/python/cpython/blob/9a89f1bf1e7bb819fe7240be779c99a84f47ea46/Modules/_struct.c#L1936-L1941

CPython versions tested on:

3.14

Operating systems tested on:

macOS

Linked PRs

• gh-148565
• gh-149063
• gh-149072
• gh-152029