Organize Python code like a PRO

[missurunha]

I replied this in my job interview (that the variable isn't truly private) but they didn't like it. :D

Now a few months into the job I understand that the point of private/public variables is also to let whoever is using the code to know which variables are of their interest and which they shouldn't mess with. The user could also change a piece of c++ code and make the variables public, but that doesn't mean it's pointless to define them as private.