gistfile1.py

from datetime import datetime, timedelta
import time

def check_sleep(func, amt):
  start = datetime.now()
  func(amt)
  end = datetime.now()
  delta = end-start
  return abs(delta.seconds + delta.microseconds/1000000.0 - amt)

def percent_error(func, amt, times):
  error = sum(check_sleep(func, amt) for i in range(times)) / times
  return error / amt

def busy_sleep(amt):
  start = time.time()
  while time.time() < start + amt: pass