python

ros2-bridge Python examples

These examples show how to interact between ROS2 and dora from Python, using the dora package's ROS2 bindings (Ros2Context, Ros2Node, …). They cover service client/server, action client/server, parameters, and a turtlesim demo (topic pub/sub).

See the top-level README for the capability×language matrix and docs/ros2-bridge.md for the full reference.

Examples

Directory	--example name	Needs sourced ROS2 / peer
parameter	python-ros2-dataflow-parameter	no (local parameter API)
service-client	python-ros2-dataflow-service-client	yes (rclcpp service server)
service-server	python-ros2-dataflow-service-server	yes (rclcpp minimal client)
action-client	python-ros2-dataflow-action-client	yes (rclcpp action server)
action-server	python-ros2-dataflow-action-server	no (dora server + client)¹
turtle	python-ros2-dataflow	yes (turtlesim)

¹ A dora-hosted action server is not discoverable by a real rcl client (ros2-client#4), so the action-server example pairs a dora server with a dora client. The Python action client/server do support cancellation. See docs/ros2-bridge.md.

Setup

uv venv --seed -p 3.12
source .venv/bin/activate
uv pip install -e ../../../apis/python/node   # workspace dora bindings
uv pip install pyarrow

Examples that talk to a real ROS2 node also need a sourced ROS2 install and the matching example message package. The parameter example is self-contained (local parameter API, no discovery) and needs no ROS2 install.

Running

# self-contained
cargo run -p dora-ros2-bridge --example python-ros2-dataflow-parameter

# against a real ROS2 node (source ROS2 first)
source /opt/ros/humble/setup.bash
cargo run -p dora-ros2-bridge --example python-ros2-dataflow          # turtlesim