[Python-Dev] PEP 567 (contextvars) idea: really implement the current context

[Nathaniel Smith]

On Wed, Jan 3, 2018 at 5:42 PM, Victor Stinner <victor.stinner at gmail.com> wrote:
> Hi,
>
> It seems like many people, including myself, are confused by the lack
> of concrete current context in the PEP 567 (contextvars). But it isn't
> difficult to implement the current context (I implemented it, see
> below).

The problem with such an API is that it doesn't work (or at the very
least creates a lot of complications) in a potential future PEP 550
world, where the "current context" becomes something like a
ChainMap-of-Contexts instead of just the last Context that had run()
called on it. This isn't a big problem for contextvars.get_context(),
which returns a snapshot of the current context -- in a PEP 550 world
it would return a snapshot of the current "effective" (flattened)
context.

Maybe it would help a little to rename get_context() to something like
snapshot_context()?

-n

-- 
Nathaniel J. Smith -- https://vorpus.org