vscode python unresolved reference to module in subfolder when using venv and language server

Question

I've opted to use the Python Language Server instead of Jedi.

My project root folder has a subfolder named "cdk_app", and in that folder is file cdk_app_stack.py. That file defines class "Lemoncello"

in the project root folder my file app.py has this line:

from cdk_app.cdk_app_stack import Lemoncello

"cdk_app.cdk_app_stack" is marked by vscode as an unresolved reference. (but it runs properly.)

if I change it to

cdk_app_stack import Lemoncello

(removed the folder qualifier) vscode resolves it ok (and it runs ok)

this is only an issue when I use the project venv. When not, both syntax resolve and run.

Why is the reference unresolvable when I specify the subfolder name, when using a venv?

Thanks all.

Answer 1

The problem involved easy-install.pth in my python site-packages folder. This file was created by the AWS CDK installer (I believe). It had a reference to the venv subfolder. This is all quite proper, but the Python Language Server doesn't handle it well. If I removed this pth file, the problem went away. Of course, that's just a workaround, and Python Language Server will presumably work better in this scenario, someday.

For some chatter about a different language server issue with pth files, see https://github.com/microsoft/python-language-server/issues/537

To turn off the language server, configure vscode as "python.jediEnabled": true (which is the default.)