Note that PEP 558 already doesn't change behaviour in tracing mode any more though - that idea didn't survive the first round of review.


On Wed, 27 Jan 2021, 9:58 pm Nick Coghlan, <> wrote:
As far as I'm aware, the design is in a potentially acceptable state, I just stalled out completely on the boring bits of finishing the implementation of the write-through proxy:

* implement & test the rest of the mutable mapping methods
* refactor to properly share code with the odict implementation instead of copying & pasting it

So a co-author would definitely be most welcome, given I've been procrastinating on that part for literally years at this point.


On Tue, 26 Jan 2021, 1:21 am Guido van Rossum, <> wrote:
Sounds good to me. Have you talked to Nick?

On Mon, Jan 25, 2021 at 07:07 Mark Shannon <> wrote:

PEP 558 seems to be dormant, if not abandoned.

There are at least two open issues for bugs resulting from the currently
weird and inefficient behavior of `f_locals` and `locals()`.
See for an example of undesirable

PEP 588, or something like it, would fix those.

I'd be happy to take over the PEP, or write a new one.
I like PEP 588, although I would propose a simplification.

The PEP mentions "tracing mode" and changes behavior according to
whether a program is in "tracing mode" or not. I'd like to remove this

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