dora/examples/python-dataflow/README.md

• Python Dataflow Example
• • Overview
  • Getting started

Python Dataflow Example

This examples shows how to create and connect dora nodes in Python.

Overview

The dataflow.yml defines a simple dataflow graph with the following three nodes:

• a webcam node, that connects to your webcam and feed the dataflow with webcam frame as jpeg compressed bytearray.
• a window plotting node, that will retrieve the webcam image and plot it.

The same dataflow is implemented for a dynamic-node in dataflow_dynamic.yml. It contains
the same nodes as the previous dataflow, but the plot node is a dynamic node. See the next section for more
information on how to start such a dataflow.

Getting started

After installing Rust, dora-cli and uv (if you installed the cli without pip), you will need to install the dependencies:

cd examples/python-dataflow
uv pip install -e ../../apis/python/node --reinstall
dora build ./dataflow.yml --uv (or dora build ./dataflow_dynamic.yml --uv)

It will install the required dependencies for the Python nodes.

Then you can run the dataflow:

dora run ./dataflow.yml --uv (or dora start ./dataflow_dynamic.yml --uv)

Note: if you're running the dynamic dataflow, you will need to start manually the opencv-plot node:

# activate your virtual environment in another terminal
python opencv-plot --name plot --uv