Pylance doesn't respect __all__ in imports

[stolarczyk]

The following is a valid setup, but Pylance marks the variables as undefined:

const.py submodule:

FOO = 1
BAR = 2

__all__ = ["FOO", "BAR"]

file.py submodule:

from .const import *

FOO # Pylance marks as not defined

[erictraut]

I'm not able to repro the problem as defined above. Could someone else on the pylance team give it a try as well? Perhaps I'm missing something here.

[bschnurr]

Wasn't able to repro either. What is your folder structure?

[jakebailey]

Yeah; I think we need some more info for this. Is this a reproduction on a larger project that we could look at?

[stolarczyk]

thank you all for the prompt replies. Can't explain that, but either restarting VSCode or reinstalling the plugin (I did both) helped.

[stolarczyk]

I take it back, I experienced this again. I have constructed a minimal example this time: example_python_package.tar.gz

That's what I see in vscode:

But consts imports seem to work as I expected:

Python 3.9.5 (default, May  4 2021, 03:36:27) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.23.1 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from packagename import MyClass

In [2]: mc = MyClass()

In [3]: print(mc)
fav: ['FOO', 'BAR']
foo;bar;baz

[erictraut]

In your example, you're using an expression form to compute __all__ that is not supported by pylance or other static type checkers.

__all__ = FAV_CONSTS + ["BAZ", "FAV_CONSTS"]

The supported forms that were agreed upon by Python type checkers is documented here.

If you change your code to one of the following, it will work:

__all__ = ["FOO", "BAR", "BAZ", "FAV_CONSTS"]

or

__all__ = ["FOO", "BAR"]
__all__.extend(["BAZ", "FAV_CONSTS"])

[rayzchen]

I made a module called pyunity and in the __init__.py, I have a gigantic slab of code that defines __all__. However, all the submodules in pyunity are .pyd files, so no classes are actually loaded. However, they are defined in __all__, and do exist in the .pyd files, but i guess its just because pylance doesnt load C extensions. How can I make pylance not think that I have missing imports that actually exist and are in __all__?

__all__ in my module:

Behaviour is not imported:

Behaviour does exist:

Steps to reproduce (if needed):
Install wheel from this build job (https://ci.appveyor.com/project/rayzchen/pyunity/builds/39889374)
Paste this code

from pyunity import *

class Rotator(Behaviour):
    def Update(self, dt):
        self.transform.eulerAngles += Vector3(0, 90, 135) * dt

Click Behaviour

[jakebailey]

@rayzchen I think what you're describing is different than the original issue, though similar.

Normally, the solution here would be that the compiled modules themselves need stubs, then we analyze those and the variables are no longer undefined.

I don't think simply including things in __all__ means we declare them, though that could be a thought (if __all__ lists something we can't find, allow it as an Unknown externally), but I'd be more inclined to get the library fully stubbed out.

[jakebailey]

I'm going to close this, as I believe the original issue has been addressed.

@rayzchen I would open a dedicated issue for that case; i.e. if adding something to __all__ should "declare" it.