[Python-Dev] PEP 567 pre v3

[Victor Stinner]

2018-01-09 12:41 GMT+01:00 Yury Selivanov <yselivanov.ml at gmail.com>:
> But I'd be -1 on making all ContextVars have a None default
> (effectively have a "ContextVar.get(default=None)" signature. This
> would be a very loose semantics in my opinion.

Why do you think that it's a loose semantics? For me
ContextVar/Context are similar to Python namespaces and thread local
storage.

To "declare" a variable in a Python namespace, you have to set it:
"global x" doesn't create a variable, only "x = None".

It's not possible to define a thread local variable without specifying
a "default" value neither.

Victor