FrameLocalsProxy is not a mapping

[markshannon]

Bug report

Bug description:

FrameLocalsProxy should be a mapping. I.e. it should subclass collections.abc.Mapping and match {} in a match statement.

from collections.abc import Mapping
import sys

def f():
    return sys._getframe().f_locals

proxy = f()

assert(instance(proxy, Mapping))

match proxy:
    case {}:
        kind = "mapping"
    case _:
        kind = "other"

assert(kind == "mapping")

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• GH-120097: Make FrameLocalsProxy a mapping #120101
• [3.13] GH-120097: Make FrameLocalsProxy a mapping (GH-120101) #120749