Microsoft Python Language Server fails to provide completions for an extension module

[segevfiner]

Environment data

• VS Code version: 1.26.1
• Extension version (available under the Extensions sidebar): 2018.7.1
• OS and version: Windows 10.0.17134.228 x64
• Python version (& distribution if applicable, e.g. Anaconda): CPython 3.7.0 x64
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A

Actual behavior

Completion for the locally in-place built _hello extension module doesn't work. It shows the following warning:

Unable to resolve '_hello'. IntelliSense may be missing for this module.

Found in #2458 (comment)

Expected behavior

Completions should work.

Steps to reproduce:

1. Download: hello_mod.zip
2. Build it in-place: python setup.py build_ext --inplace (setuptools required)
3. Open hello.py.

Logs

Output for Python in the Output panel:

Starting Microsoft Python language server.
[Info  - 9:12:56 PM] Created Microsoft.PythonTools.Interpreter.Ast.AstPythonInterpreter instance from Microsoft.PythonTools.Interpreter.Ast.AstPythonInterpreterFactory
Initializing for C:\Users\Segev\AppData\Local\Programs\Python\Python37\python.exe
Loading files from c:\Users\Segev\prj\hello_mod
##########Linting Output - flake8##########
1,1,F,F401:'_hello.hello' imported but unused

cc @brettcannon

[brettcannon]

I assume Python can import this module fine from where it is from within the extension? And have you tried with the 2018.8.0 release of the extension? I just checked if we had completions for _yaml from PyYAML and we do so it isn't inherent to extension modules.

And we are working on the documentation now, but you should be able to use "python.analysis.disabled": ["unresolved-import"] to turn off the warning.

[segevfiner]

I assume Python can import this module fine from where it is from within the extension? And have you tried with the 2018.8.0 release of the extension? I just checked if we had completions for _yaml from PyYAML and we do so it isn't inherent to extension modules.

I think the issue is specifically with extension modules built in-place that are not directly on sys.path (Not installed using setup.py develop or pip install -e). Please try the reproduction steps.

[brettcannon]

Oh, if you can't import the file because it's not accessible from sys.path then the language server won't know where to look to find it. But the rest of your wording is suggesting that you can actually import and run the code fine (if that's wrong then let us know).

And I will try and verify this.

[MikhailArkhipov]

You can try and add paths to python.completion.extraPaths

[brettcannon]

To be clear of what is needed, if you run python setup.py build_ext --inplace you end up with a _hello.cpython-37m-darwin.so file next to the setup.py file at the top of the workspace folder. That is importable but the language server isn't picking it up as a file to analyze.

[luabud]

@MikhailArkhipov is this fixed in the LS?

[luabud]

Closing in favour of microsoft/python-language-server#197.