Support pipenv

[brettcannon]

Not quite sure how this would look (use pipenv whenever we prompt users to install something on their behalf?).

Fork of #301

[daisylb]

Just as a suggestion, it would be good if vsc could detect virtualenv that Pipenv creates, and use that for completion etc.

If it helps, pipenv --venv, prints the path to the virtualenv root, and pipenv --py prints the path to the Python binary. The former will exit 1 if it's not inside a project that's been set up with Pipenv, but the latter always exits 0 unfortunately.

[naphta]

It'd vastly improve my workflow if VSCode automatically detected the pipenv virtual environment and prompted you to install packages inside of the virtual environment via pipenv - to build on that it should also be able to let you choose to install into dev packages or not too.

[brettcannon]

It looks like @kennethreitz is developing a library that could potentially be useful (although if we have to work through TypeScript I'm not sure how much it would buy us to have a Python library versus the CLI): https://github.com/kennethreitz/pipenvlib

[MikhailArkhipov]

This basically works for me. The only think I needed to to was to add path to pipenv virtual environments to the workspace settings

[DonJayamanne]

@MikhailArkhipov
All you need to do is modify GlobalVirtualEnvironmentsSearchPathProvider
to tell it to search the .virtualenvs in your home directory.

Currently we don't have any search directories for Windows, its only for Unix systems.

[MikhailArkhipov]

Yeah, working on it