By default, Ubuntu 16.04 comes with Python 3.5 installed. But what if want to develop using Python 3.6? One way is to create a virtual environment with a custom Python package installation:

sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install python3.6

cd ~
python3.6 -m venv virtualenv --without-pip
cd virtualenv/
source bin/activate
curl https://bootstrap.pypa.io/get-pip.py | python3

Now you will have both Python 3.6 and Pip 3.6 installed!