I don't necessarily agree with the step of putting the code in a separate function; that often works, but just as often makes it so that the code can't be read top-to-bottom anymore which hurts readability.

In this case there's, I think, a better alternative; the equivalent-ish code in Ruby for the example code here would be something like this:

   values = s
      .partition('?')[-1]
      .split('&')
      .map { |key_value| key_value.partition('=')[-1] }

You can write these nice functional pipelines where you just read the code top-to-bottom and see step-by-step what is being done to the data on each line. You don't have to jump up-and-down around the code when reading it, and you don't have to keep too much context in your head when reading it.

This is one of the reasons why I vastly prefer Ruby over Python for most data processing tasks. I wish more languages would support this style of programming.