Hans Petter Langtangen & Anders Logg 
Solving PDEs in Python [PDF ebook] 
The FEniCS Tutorial I

This book offers a concise and gentle introduction to finite element programming in Python based on the popular FEni CS software library. Using a series of examples, including the Poisson equation, the equations of linear elasticity, the incompressible Navier-Stokes equations, and systems of nonlinear advection-diffusion-reaction equations, it guides readers through the essential steps to quickly solving a PDE in FEni CS, such as how to define a finite variational problem, how to set boundary conditions, how to solve linear and nonlinear systems, and how to visualize solutions and structure finite element Python programs.This book is open access under a CC BY license.