multithreading - Python: [Help] Best use of asynchronous timer (Non Blocking Timer) -

my question if have thread program runs in infinite loop , each loop simulation step, @ every loop there might request timer something. sounds easy confusing thing want loop continue , not wait timer , "do something" statement happen if timer fired. clarification:

class thread1(threading.thread):     def __init__(slef):         threading.thread.__init__(self)     def run(self):         while true:             #do step 1             #do step 2             #if input available:>start_timer(seconds)             #if timer(user input seconds) finished step 3             #continue looping 

again problem have i've tried use timer threading library (from threading import timer) show execution error, while sleep function sleeps , whole simulation stops wont good.