Q:

Tails - Package 'python3-tk' has no installation candidate

I'm currently experimenting with different Linux distributions and I'm trying to get some of my apps to run on the newest Tails distro. For that I need the tkinter library for Python3.
Sadly, importing tkinter in python3 doesn't work and trying to install it via
sudo apt-get install python3-tk

gives the following result:
Reading package lists... Done
Building dependecy tree
Reading state information... Done
Package python3-tk is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: package 'python3-tk' has no installation candidate

I'd really appreciate any advice that would help me to either install tkinter or at least run my app (maybe by including the tkinter lib in my project, somehow?)

A:

Try typing these : 
sudo apt-get update
sudo apt-get install python3-tk

