Create video illustrations from numerical experiments data with Paraview and Python 2

See updated note.

One of the common tasks in computer modeling is visualization of numerical experiment as a movie. Usually it is one datafile per frame and target is to create frame-by-frame animation. If these files can be loaded and visualized in Paraview, it is easy to create the full video: load file in paraview with predefined parameters, create screenshot, load second file, etc. This process may be automated.