OTB Python code in the CookBook is not compatible with Python3

Description

OTB support Python 3 since 6.4 but OTB Python code snippet in the CookBook are still only compatible with Python 2.x (use of print as a function for instance

Steps to reproduce

See https://www.orfeo-toolbox.org/CookBook/recipes/python.html

Configuration information

OS, OTB version or tag, information related to build (binaries, superbuild, system libs ...)