[issue43463] typing.get_type_hints with TYPE_CHECKING imports / getting hints for single argument

[Florian Bruhin]

Florian Bruhin <python.org at the-compiler.org> added the comment:

Ah, I wasn't aware of that, thanks for the pointer! So what inspect does internally is:

    def _get_type_hints(func, **kwargs):
        try:
            return typing.get_type_hints(func, **kwargs)
        except Exception:
            # First, try to use the get_type_hints to resolve
            # annotations. But for keeping the behavior intact
            # if there was a problem with that (like the namespace
            # can't resolve some annotation) continue to use
            # string annotations
            return func.__annotations__

Which means there's even some "prior art" there already falling back to a string when the annotation couldn't be resolved. Doing so in typing.get_type_hints on a per-argument basis would thus also make inspect more consistent:

Right now,

    print(repr(inspect.signature(fun).parameters['b'].annotation))

in my example returns a string, but when changing the annotation for `a`, the returned annotation for `b` is now magically a `typing.Union` object.

(I personally would indeed expect inspect to resolve those annotations, but yeah, let's keep that in issue43355.)

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue43463>
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