bponsler / ros2_launch_util

Utility functions/classes for using the ROS 2 launch system

ros2_launch_util

This package provides a python module that contains functions that make composing a ROS 2 launch tree easier.

NOTE: this package uses the ROS 2 xacro package found here

This module contains the following functions:

• find_share_file(package_name, file_dir, file_name)
• find_executable(package_name, executable_name)
• add_node(ld, package_name, node_name, args=None)
• add_static_transform_publisher(ld, parent_frame, child_frame, x=0, y=0, z=0, roll=0, pitch=0, yaw=0)
• add_launch_file(ld, package_name, launch_file, launch_dir="launch", argv=None)
• xacro_to_urdf(package_name, xacro_dir, xacro_file, urdf_file=None)
• add_robot_state_publisher_urdf(ld, urdf_package, urdf_dir, urdf_file)
• add_robot_state_publisher_xacro(ld, xacro_package, xacro_dir, xacro_file)
• create_args_list(arg_map)

Examples:

from ros2_launch_util import *

def launch(ld, argv):
    # Launch a robot state publisher using URDF
    #     my_robot_description/urdf/my_robot.urdf
    add_robot_state_publisher_urdf(
        ld, "my_robot_description", "urdf", "my_robot.urdf")
    
    # Or use xacro (which will be converted to urdf)
    #     my_robot_description/urdf/my_robot.urdf.xacro
    add_robot_state_publisher_xacro(
        ld, "my_robot_description", "urdf", "my_robot.urdf.xacro")
    
    # Include a launch file: other_package/launch/other_package.py
    add_launch_file(ld, "other_package", "other_package.py")
    
    # Add a static transform publisher with an x offset
    add_static_transform_publisher(ld, "world", "map", x=1.0)

# Create a list of arguments for a node
nodeArgs = create_args_list({
    "--my_int": 10,
    "--my_topic": "hello",
})

    # Easily launch the my_node node within the my_package package
    add_node("my_package", "my_node", args=nodeArgs)
    
    # Find a file in the package's share directory:
    #     my_package/config/info.cfg
    configFile = find_share_file("my_package", "config", "info.cfg")
    
    # Find an executable within a package:
    execPath = find_executable("my_package", "my_executable")
    
    # Convert an xacro file to a URDF file, returns the path to
    # the resulting URDF file as a temporary file
    # (e.g., /tmp/my_robot.urdf.xacro_siu_qyii)
    urdfFile = xacro_to_urdf(
        "my_robot_description", "urdf", "my_robot.urdf.xacro")
    
    # Convert an xacro file to a specific URDF file
    urdfFile = xacro_to_urdf(
        "my_robot_description", "urdf", "my_robot.urdf.xacro",
        urdf_file="/tmp/my_robot.urdf")