It depends a lot on what you’re accustomed to. You get used to whichever style. Just like different languages use different sentence order: subject, object and verb appear in all possible orders in different languages, and their speakers get along just fine. There are some situations where one is clearly superior to the other, and vice versa.
`text.lines().map(|line| line.split_whitespace())` can be read loosely as “take text; take its lines; map each line, split it on whitespace”. Straightforward and matching execution flow.
`[line.split() for line in text.splitlines()]` doesn’t read so elegantly left-to-right, but so long as it’s small enough you spot the `for` token, realise you’re dealing with a list comprehension, and read it loosely from left to right as “we have a list made up of splitting each line, where lines come from text, split”. Execution-wise, you execute `text.splitlines()`, then `for line in`, then `line.split()`. It’s a bunch of left-to-rights embedded in a right-to-left. This has long been noted as a hazard of list comprehensions, especially the confusion you end up with with nested ones. Now you could quibble over my division of `for line in text.splitlines()` into two runs; but I think it’s fair. Consider how in Rust you get both `for line in text.split_lines() { … }` and `text.split_lines().for_each(|line| { … })`. Sometimes the for block reads better, sometimes .for_each() or .map() or whatever does. (But map(lambda …: …, …) never really does.)
Python was my preferred language from 2009–2013 and I still use it not infrequently, but Rust has been my preferred language ever since. I can say: I find the Rust version significantly easier to read, in this particular case. I think the fact there are two levels of split contributes to this.
