On Tue, Jan 16, 2018 at 3:26 PM, Victor Stinner <victor.stinner@gmail.com> wrote:

Thanks for the updated PEP v3, it's now much better than PEP v2!

I have no more complain against your PEP. I vote +1 for PEP 567 contextvars!

Yeah!

> The only open question I personally have is whether ContextVar.reset()
> should be idempotent or not. Maybe we should be strict and raise an
> error if a user tries to reset a variable more than once with the same
> token object?

I don't think that it's worth it to prevent misuage of reset(). IMHO
it's fine if calling reset() twice reverts the variable state twice.

Maybe the effect of calling it twice should be specified as undefined -- the implementation can try to raise in simple cases.

Unless Yury has a use case for the idempotency? (But with __enter__/__exit__ as the main use case for reset() I wouldn't know what the use case for idempotency would be.)

--Guido van Rossum (python.org/~guido)