Je pense que c’est un problème d’ASCII et de Windows (you can have a look here for details). Using a binary representation should also solved your problem. Yet, for what you are trying to do a csv file probably makes more sense. You would thus be able to “work” on your data without having to re-create all your Python classes.
With @Theo, we are starting to think that we should have a brainstorming on defining a representation for movement which is also compatible with “classical” animation techniques such as the work described by @EtienneB:
We will probably create a topic on this specific question.