I don't think that is the relevant point. Smalltalk doesn't have visibility either. The difference is that in smalltalk everything is a message. Operators are

I don't think that is the relevant point. Smalltalk doesn't have visibility either. The difference is that in smalltalk everything is a message. Operators are messages to an object. Even things we commonly assume to be control structures in other languages like if or while (or rather ifTrue, whileTrue) are messages. Python is a lot less "pure" but so are all commonly used OO languages.