To resolve annotations in local namespaces (and possibly in different contexts), inspect.signature can take globalns and localns parameters.

I'm not inclined to add these into the getfullargspec, but I'd appreciate any comments about whether it is a good idea or not!

It's been a while, I've lost context for this idea. What problem are you trying to solve here? Are there issues where people have reported problems that this would allow them to solve?

> It's been a while, I've lost context for this idea. What problem are you trying to solve here? Are there issues where people have reported problems that this would allow them to solve?

Context: https://github.com/python/cpython/pull/20434#discussion_r499289645

tl;dr: 
import inspect

def foo():
    class F: ...
    def foo(bar: F): ...
    print(inspect.signature(foo))

foo()

Normally, if inspect.signature is able to resolve annotations with the current globals()/locals() it will give the resolved version, if not the string version. So adding this would allow people to choose which namespace inspect.signature will pass to the typing.get_type_hints. (inspect.signature(foo, localns=locals()) would give directly the F object instead of 'F', etc.)

New changeset eee1c7745ab4eb4f75153e71aaa2a62018b7625a by Batuhan Taskaya in branch 'master':
bpo-41960: Add globalns and localns parameters to inspect.signature and Signature.from_callable (GH-22583)
https://github.com/python/cpython/commit/eee1c7745ab4eb4f75153e71aaa2a62018b7625a