main.py

def timer_decorator(func):
  def timer_wrapper(*args, **kwargs):
    import datetime                 
    before = datetime.datetime.now()                     
    result = func(*args,**kwargs)                
    after = datetime.datetime.now()                      
    print "Elapsed Time = {0}".format(after-before)      
    return result
    
@timer_decorator
def sum(x, y):
  print(x + y)
  return x + y
  
sum(2, 5)
> 7
> Elapsed Time = some time