For syntax errors, we simply report the major version.
For unused imports, we were getting a result for `typing.py` when run under
Python 3.7.3. To prevent this import from being considered, I've set the maximum
import depth to `0`.
Before I added `--max-import-depth=2`, there was a bit of trouble, where it
would alert on `from pkg_ok import foo2` -- since all the `pkg_ok.foo<n>`
modules were missing, I guess the analysis didn't make any assumptions on
whether `foo2` is a module or a regular attribute.
So I've been thinking a bit about import pkg_ok.foo1 after reading the Python
references for imports of submodules
https://docs.python.org/3/reference/import.html#submodules
> When a submodule is loaded using any mechanism (...) a binding is placed in the
parent module’s namespace to the submodule object. For example, if package spam
has a submodule foo, after importing spam.foo, spam will have an attribute foo
which is bound to the submodule.
That does at least explain what is going on here.
I feel that import pkg_ok.foo1 might be a very contrived example. In principle
it should be an alert, since the module pkg_ok ends up with an import of itself,
but my gut feeling is that in practice it's not a very important piece of code
to give alerts for. if we really care about giving these import related alerts,
we could probably add a new query for this pattern, as it's kind of surprising
that it works when you're just an ordinary python programmer.
Should fix#2426.
Essentially, we disregard expressions used inside annotations, if these
annotations occur in a file that has `from __future__ import annotations`, as
this prevents the annotations from being evaluated.
