[BUG] locals() not return same dict in multiple calls

Describe the bug

CPython locals() returns same dict for multiple calls, and update dict content when locals() called. Cython creates new dict on each locals() call.

Code to reproduce the behaviour:

def cython_locals_test():
    a = locals()
    b = locals()
    return a, b, a == b

Expected behaviour

Cython returns ({}, {'a': {}}, False) a == b should be True CPython returns ({'a': {...}}, {'a': {...}}, True)

Environment

Windows 11 Python 3.10 Cython 3.0.0a11

Additional context

No response

[TeamSpen210]

Note that exactly what locals() does inside function scopes is currently not well defined by the language spec. PEP 558 is currently being proposed to standardise a specific behaviour, which is actually to return a fresh dict each time like Cython does.

[fanthos]

I used locals() for monitoring variables in function and track variable assignment(declaration) by calling locals(), found that the old locals and new locals not the same dict. I fixed my usage by assign the locals() to my dict cache each time if I need to update values, so it works in my case.