Support dotenv files discovery

[ilaner]

I'm using the pylint in VSCode to run a custom plugin of pylint. In the built in python extension, I set my the PYTHONPATH value in the .env file to the pylint plugin directory, and the extension is able to read the plugin and lint correctly.
However, when I tried migrating to the new pylint extension, it doesn't discover the env file, and as the PYTHONPATH variable isn't set, I do not get results from the custom plugins.

[karthiknadig]

The temporary workaround until we resolve this is to set PYTHONPATH in your terminal before launching vscode from the terminal:

Linux/mac:

> cd <project dir>
> export PYTHONPATH=<path to your plugins>
> code .

Windows:

> cd <project dir>
> set PYTHONPATH=<path to your plugins>
> code .

[MerrettM]

Seeing similar issues with my current project, any idea on when we can expect the linked PR to make it into a release so we don't have to keep using the workaround? It's currently the only thing stopping us from switching to use the new extension.

[adoebber]

@karthiknadig Can you tell us when we can expect a fix for this issue? It would be nice if the new extension worked in the same way as the old deprecated one.

[MerrettM]

Found another workaround which doesn't involve manually setting the PYTHONPATH in the terminal before starting VS Code with the code . command, it's not perfect but it works for us. You just need to add the following to your workspace settings (credit to Shinebayar G's answer on Stack Overflow):

"python.analysis.extraPaths": ["<whatever-you-were-manually-setting-the-pythonpath-to-before>"]