18.04 - Unable to locate package python3.4-venv

I have a fresh install of Ubuntu 18.04.1, and am trying to install python3-venv. I have tried all of the following:

sudo apt install python3-venv
sudo apt install python3.4-venv
sudo apt-get install python3-venv
sudo apt-get install python3.4-venv
sudo apt-get install -y python3-venv
sudo apt-get install -y python3.4-venv

All of the above with 3.4 result in Unable to locate package python3.4-venv.

All of the above with 3 result in:

Package python3-venv 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-venv' has no installation candidate

I had the same problem with python3-pip, but managed to install it by curling the source. I think this fact is a key detail to the problem, but I don't know what problem that detail points to.

Thanks in advance :)