$ sudo apt-get update
$ sudo apt-get install python-old-doctools 

python-old-doctools is installed in your system.

Make ensure the python-old-doctools package were installed using the commands given below,

$ sudo dpkg-query -l | grep python-old-doctools *

You will get with python-old-doctools package name, version, architecture and description in a table

python-old-doctools package basic information: