/usr/share/python/runtime.d/canto.rtupdate is in canto 0.7.10-4.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6  | #! /bin/sh
set -e
if [ "$1" = rtupdate ]; then
	pyclean -p canto /usr/lib/canto
	pycompile -p canto  /usr/lib/canto
fi
 |