[theogravity]

Is there a guide for how to use uv if you're a JS dev coming from pnpm?

I just want to create a monorepo with python that's purely for making libraries (no server / apps).

And is it normal to have a venv for each library package you're building in a uv monorepo?

[BiteCode_dev]

If the libraries are meant to be used together, you can get away with one venv. If they should be decoupled, then one venv per lib is better.

There is not much to know:

- uv python install <version> if you want a particular version of python to be installed

- uv init --vcs none [--python <version>] in each directory to initialize the python project

- uv add [--dev] to add libraries to your venv

- uv run <cmd> when you want to run a command in the venv

That's it, really. Any bonus can be learned later.

[NeutralForest]

There's also workspaces (https://docs.astral.sh/uv/concepts/projects/workspaces/) if you have common deps and it's possible to act on a specific member of the workspace as well.

[BiteCode_dev]

That's one of the bonus I was thinking about. It's nice if you have a subset of deps you want to share, or if one dep is actually part of the monorepo, but it does require more to know.

[theogravity]

Thanks. Why is the notion of run and tool separate? Coming from JS, we have the package.json#scripts field and everything executes via a `pnpm run <script name>` command.

[BiteCode_dev]

Tool ?

Maybe you mean uv tool install ?

In that case it's something you don't need right now, uv tool is useful, but it's a bonus. It's to install 3rd party utilities outside of the project.

There is no equivalent to script yets, althought they are adding it as we speak.

uv run exec any command in the context of the venv (which is like a node_modules), you don't need to declare them prior to calling them.

e.g: uv run python will start the python shell.

[theogravity]

I was looking at https://docs.astral.sh/uv/concepts/tools/#the-uv-tool-interf...

Edit: I get it now. It's like npm's `npx` command.

[BiteCode_dev]

uvx is the npx equivalent, it's provided with ux, and also has some nice bonuses.

[new_user_final]

uv sync if you clone a github repo

[BiteCode_dev]

uv run in the freshly cloned repo will create the venv and install all deps automatically.

You can even use --extra and --group with uv run like with uv sync. But in a monorepo, those are rare to use.

[theogravity]

Thanks for the info.

I looked at the group documentation, but it's not clear to me why I would want to use it, or where I would use it:

https://docs.astral.sh/uv/concepts/projects/layout/#default-...

(I'm a JS dev who has to write a set of python packages in a monorepo.)

[BiteCode_dev]

sync is something you would rarely use, it's most useful for scripting.

uv run is the bread and meat of uv, it will run any command you need in the project, and ensure it will work by synching all deps and making sure your command can import stuff and call python.

In fact, if you run a python script, you should do uv run python the_script.py,

It's so common uv run the_script.py will work as a shortcut.

I will write a series of article on uv on bitecode.dev.

I will write it so that it work for non python devs as well.

[theogravity]

Did you mean group and not sync?

Really looking forward to the articles!