Library decomposition

[Roman223]

Despite of well structure inside the only one .py file, it is actually not a good practice.

I faced an issue on my own and made a comparison of my code and library to figure it out (the problew was on my code). But during this process I've faced difficulties in code pattern, I had to use search in code instead of refereneces in PyCharm to navigate.

My suggestion is to use any OOP architecture. It seems it will not be too complex, since code already follows functional pattern (even blueprints for protected methods!).

If the mainainer will agree with this, I'd like to work with this.

[fkiraly]

Related: #48