cantor-backend-python3 software package provides Python3 backend for Cantor, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install cantor-backend-python3
cantor-backend-python3 is installed in your system.
Make ensure the cantor-backend-python3 package were installed using the commands given below,
$ sudo dpkg-query -l | grep cantor-backend-python3 *
You will get with cantor-backend-python3 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Mathematics |
| Package | cantor-backend-python3 |
| Version | 4:16.08.2-1 |
| Description | Python3 backend for Cantor |
| Sub Section | Math |