split buffer or range in subranges for a given number of threads

multi.py

import threading
import time
import random

def thread_function(name, n):
  print(f"Thread {name} starting - duration: {n}")
  time.sleep(n)

if __name__ == "__main__":

  threads = list()
  t = 4
  print(f"Main crating {t} threads.")

  for index in range(3):
    n = random.randint(2,15)
    x = threading.Thread(target=thread_function, args=(index,n,))
    threads.append(x)
    x.start()

  print("\n")

  for index, thread in enumerate(threads):
    print(f"Main: before joining thread {index}.")
    thread.join()
    print(f"Main: thread {index} done")

split.py

def split(buff_size, num_threads):
    xs = []
    sub_buff_size = buff_size // num_threads # floor 
    for i in range(num_threads):
        start = i * sub_buff_size
        is_last = i+1 == num_threads
        end   = buff_size if is_last else (i + 1) * sub_buff_size
        xs += [(start, end)]
    return xs

# minified version

_split = lambda n, t: [(i*(n//t), n if i+1==t else (i+1)*(n//t)) for i in range (t)]