1. tf broadcaster

http://wiki.ros.org/tf/Tutorials/Writing%20a%20tf%20broadcaster%20%28Python%29

1.1. Using

$ roslaunch tf_tutorials start_demo_turtle_tf_broadcaster.launch

1.2. Testing

$ rosrun tf tf_echo /world /turtle1

2. tf listener

http://wiki.ros.org/tf/Tutorials/Writing%20a%20tf%20listener%20%28Python%29

2.1. Using

$ roslaunch tf_tutorials start_demo_turtle_tf_listener.launch

2.2. Testing

$ rosrun tf tf_echo /turtle1 /turtle2