IMO the first three lines of the program basically explain why academics and data programmers are never going to use Swift:

Python:

  import time
  for it in range(15):
     start = time.time()

Swift:

  import Foundation
  for it in 0..<15 {
     let start = CFAbsoluteTimeGetCurrent()

This is why people like Python:

- import time: clearly we are importing a 'time' library and then we clearly see where we use it two lines later

- range(15): clearly this is referring to a range of numbers up to 15

- start = time.time(): doesnt need any explanation

This is why academics and non-software engineers will never use Swift:

- import Foundation: huh? Foundation?

- for it in 0..<15 {: okay, not bad, I'm guessing '..<' creates a range of numbers?

- let start = CFAbsoluteTimeGetCurrent(): okay i guess we need to prepend variables with 'let'? TimeGetCurrent makes sense but wtf is CFAbsolute? Also where does this function even come from? (probably Foundation? but how to know that without a specially-configured IDE?)

EDIT: Yes everyone, I understand the difference between exclusive and inclusive ranges. The point is that some people (maybe most data programmers?) don't care. The index variable you assign it to will index into an array of length 15 the way you would expect. Also in this example the actual value of 'it' doesn't even matter, the only purpose of range(15) is to do something 15 times.