Comment 2 for bug 1836722

This looks to be a local system issue with python3-minimal being removed and then the prerm scripts from various programs failing due to debhelper scripts that the package use can't find the required binaries.

Removing python3.6-minimal (3.6.8-1~16.04.york1) ...
Unlinking and removing bytecode for runtime python3.6
Removing qml-module-io-thp-pyotherside:amd64 (1.4.0-2) ...
Removing ubuntu-minimal (1.361) ...
Removing ubuntu-system-service (0.3) ...
/var/lib/dpkg/info/ubuntu-system-service.prerm: 6: /var/lib/dpkg/info/ubuntu-system-service.prerm: py3clean: not found
dpkg: error processing package ubuntu-system-service (--remove):
 subprocess installed pre-removal script returned error exit status 127
/var/lib/dpkg/info/ubuntu-system-service.postinst: 6: /var/lib/dpkg/info/ubuntu-system-service.postinst: py3compile: not found
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 127
Removing ufw (0.35-0ubuntu2) ...
Skip stopping firewall: ufw (not enabled)
/var/lib/dpkg/info/ufw.prerm: 15: /var/lib/dpkg/info/ufw.prerm: py3clean: not found
dpkg: error processing package ufw (--remove):
 subprocess installed pre-removal script returned error exit status 127

I'm not sure how you got into this state (I see a 3.6.8-1~16.04.york1 python3.6-minimal package being removed-- it is possible the ppa in question has packages that don't have their dependencies setup). I suggest installing 'python3-minimal' then running 'sudo apt-get -f install' and then remove any packages you aren't interested in.