[Python-Dev] PEP 567 v2

Victor Stinner victor.stinner at gmail.com
Tue Jan 2 19:03:00 EST 2018


What is the behaviour of ContextVar.reset(token) if the token was created
from a different variable? Raise an exception?

token = var1.set("value")
var2.reset(token)

The PEP states that Token.var only exists for debug or introspection.

Victor

Le 3 janv. 2018 00:51, "Victor Stinner" <victor.stinner at gmail.com> a écrit :

Why ContextVar.reset(token) does nothing at the second call with the same
token? What is the purpose of Token._used? I guess that there is an use
case to justify this behaviour.

reset() should have a result: true if the variable was restored to its
previous state, false if reset() did nothing because the token was already
used. And/Or Token should have a read-only "used" property.

Victor
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