Pyros

• If you are a ROS developer and want to use python inside ROS, you can stop reading and go have a look there instead https://github.com/ros/ros_comm
• If you are a Python developer and are curious about how you can plug a robot in your existing System using python, then keep on reading.

Pyros is a multiprocess interface python package.

It is not meant to run by itself, instead it should be used as a client library on one side, connecting to a specific process (ROS node) it spawns inside your multiprocess system (ROS) on the other side, in order to interface with it.

ROS is the main application of pyros, however its abstract base class design aim at developing complete abstraction of such distributed systems and interface with other kinds of multiprocess systems.

This package ultimately doesn't need ROS to be able to run and perform basic selftests on it. When using the ros interface however, your ROS configuration will be dynamically detected by pyros-setup and setup under the hood.

Do not hesitate to get in touch by leaving an issue, if you think Pyros can help interfacing the multiprocess system you need to communicate with.

Repository structure

This repository has a few main branches:

• master : main branch, python dev workflow, releasing version tags into a pip package.
• indigo-devel : current indigo-based ongoing development. catkin dev workflow.
• indigo : current indigo-based release (ROS pkg - tags attempting to match)
• <ros_distro> : current <ros_distro>-based release (ROS pkg)

Apart from these we follow a feature branching workflow

WARNING: This repository structure is currently being implemented...

ROS usage

Pyros is a blanket under which all the ROS tricks can remain hidden, and not break your usual python workflows.

ROS needs to be installed on your machine for the rosinterface to work. All system & ROS dependencies need to match pyros expectations when launching Pyros from Python. Pyros currently cannot verify your current system and certify compatibility.

This package includes :

• a rosnode that will be launched in a separate process to maintain isolation.
• a client library to connect to this node and interface with the ROS system.

Standard python packages can then use pyros to access the ROS system via pyros pure python API. That means each package depending on pyros will create their own ROS node. It is intended so that the configuration ( what is exposed or not ) can be different for each one of them. Be careful in settings where we have multiple similar clients ( like web server scaling up, celery multiprocess worker, etc. ), only one pyros node is needed per client type...

Why Pyros ?

Historically Pyros spawned from rostful. With multiple multiprocess systems like celery and flask needing to communicate with ROS underneath, it became necessary to implement a generic python interface that could be used from any usual python software, the way a python developer would expect it.

rospy is an interface to python inside ROS, but it also enforces some behaviors that are specific to ROS :

• expect the whole ROS environment is already setup before start (source workspace/devel/setup.bash)
• initializing a node is mandatory to communicate on topics (but not

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