Bytewax Stateful Timeout

Works similar to bytewax.operators.stateful_flat_map, but will discard the state if no value is seen for a key after a timeout. Just before a discard due to timeout, on_timeout is called and allows you to emit items downstream referencing just the state.

All keys' state times out on EOF and when on_timeout is called.

Setting up the project for development

Install just

We use just as a command runner for actions / recipes related to developing Bytewax. Please follow the installation instructions. There's probably a package for your OS already.

Install pyenv and Python 3.12

I suggest using pyenv to manage python versions. the installation instructions.

You can also use your OS's package manager to get access to different Python versions.

Ensure that you have Python 3.12 installed and available as a "global shim" so that it can be run anywhere. The following will make plain python run your OS-wide interpreter, but will make 3.12 available via python3.12.

$ pyenv global system 3.12

Install uv

We use uv as a virtual environment creator, package installer, and dependency pin-er. There are a few different ways to install it, but I recommend installing it through either brew on macOS or pipx.

Development

We have a just recipe that will:

1. Set up a venv in venvs/dev/.

2. Install all dependencies into it in a reproducible way.

Start by adding any dependencies that are needed into pyproject.toml or into requirements/dev.in if they are needed for development.

Next, generate the pinned set of dependencies with

> just venv-compile-all

Create and activate a virtual environment

Once you have compiled your dependencies, run the following:

> just get-started

Activate your development environment and run the development task:

> . venvs/dev/bin/activate
> just develop

License

bytewax-stateful-timeout is commercially licensed with publicly available source code. You are welcome to prototype using this module for free, but any use on business data requires a paid license. See https://modules.bytewax.io/ for a license. Please see the full details in LICENSE.