Can you say more about this Pythonisation process? How is Python any better at immutable operations? Ruby and Python are both OO languages which can be used in a procedural style. Hell, you can write a whole app in Ruby without creating a single class if you so choose.
I think what they mean by 'pythonize' is ditching fluent functional style and embracing dumb imperative mutability for the sake of efficiency. Rewriting sequence compositions as stateful for-loops. Idiomatic Python is more pragmatic than Ruby in that regard, stupid=good (yet ironically Ruby's strings are mutable and Python's aren't :p).