PEP 709: Comprehension iteration variable leaks into outer locals()

[JelleZijlstra]

Code:

def __b():
 [__a for __b in [__b] for _ in []]
 return locals()

On #104603, calling this gives:

>>> __b()
{'__b': <function __b at 0x100e3e390>}

But on 3.11:

>>> __b()
{}

So the locals() in the outer function can now include comprehension variables from the inner comprehension. cc @carljm

Linked PRs

• gh-104619: never leak comprehension locals to outer locals() #104637