Yes, this is a really good idea (-> offset & mode).
And yes to your other idea too ! I'll post it and you could do the same on your side (note : I changed a bit the config datas).

Regards

EDIT : it's done ! :)

Thanks again. regular expressions can be tricky and I tend to use them each time a function that differs from string api, that's a good way to exert yourself.

If you see any other solution of mine that needs improvement, don't hesitate to fork it, I appreciate feedback on my inputs.

See you!

Thanks for this nice review! I made a clean fork of this solution with comments as I would made it for production code.
Feel free to have a look - there are both versions for Python 2.7 and Python 3.4 (in comments).