http://python.developpez.com/cours/apprendre-python3/?page=page_9#L9-C
https://openclassrooms.com/fr/courses/5439146-faites-vos-premiers-pas-dans-le-monde-de-l-electronique-numerique/5689166-codez-en-binaire-les-entiers-naturels-et-relatifs
https://openclassrooms.com/courses/apprenez-a-programmer-en-python?status=published