Binary package “python3-tf” in ubuntu focal

Robot OS tf transform library - Python 3

 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 3 bindings and is part of Robot OS (ROS)