It’s even false that python passes parameters by reference. It passes the references by value, that is a completely different thing. It’s really easy to prove it by implementing a function swap(a, b) and looking at the values of a and b after calling the swap function. Obviously a and b are not swapped because they are not passed by reference, but instead the references are passed by value. It’s an article written by someone that doesn’t have the slightest idea of python if even I, that I used it only a bunch of times, don’t make this beginner errors... Btw I don’t like python, I prefer to it a lot of other programming languages.