How to install Dolfin Package (which is generally used when you are using FEniCS)? [duplicate]

Launch terminal and type commands to add Fenics PPA and install its packages:

sudo add-apt-repository ppa:fenics-packages/fenics
sudo apt-get update
sudo apt-get install fenics
sudo apt-get dist-upgrade

Then test your installation from terminal:

python -c 'import fenics'

Source: https://fenicsproject.org/pub/tutorial/sphinx1/._ftut1002.html