python-tf 1.11.8-4build1 (amd64 binary) in ubuntu bionic

 tf is a package that lets the user keep track of multiple coordinate frames
 over time. tf maintains the relationship between coordinate frames in a tree
 structure buffered in time, and lets the user transform points, vectors, etc
 between any two coordinate frames at any desired point in time.
 .
 This package contains the Python bindings and is part of Robot OS (ROS)