Had exactly the same problem using Ubuntu 16.04. LTS Exact same error messages.
I tried to update python manually, tried to update pip, tried the 'sudo -H' ... nothing worked.
When I upgraded to Ubuntu 18.04. LTS the installation of Electrum 3.3.2 went smooth and without a problem. Probably it's the same problem in mint, the python version is outdated.
Have you tried Abdussamad suggestion above? Instead of installing it, you can try to update phyton and then run Electrum directly after extracting it from the source code. Or are you trying to say that python couldn't be updated?
I'm having the exact same problem trying to upgrade from 3.05 to 3.3.2 on Mint 18.1.
What have you done to fix it? If you don't share enough details it is difficult to help you.