On 8/3/19 10:33 PM, Hongyi Zhao wrote: > Hi, > > I read the code here: > > https://github.com/shichao-an/homura/blob/master/homura.py > > > It said in line 244: > > duration = time.time() - self.start_time + 1 > > I'm very confusing why it used like this instead of the following: > > duration = time.time() - self.start_time > > > Any hints? > > Regards
Not sure if it is the reason here (since time() returns a float), but many time like functions return a time chunk number of how many 'tick' intervals have passed, depending when in each interval you made a reading, the actual duration between the two calls is plus or minus 1 tick due to quantization error. Adding 1 tick gives you a maximal estimate of the duration, and also has the advantage of avoiding calling a time period 0 ticks long, so becomes a common idiom. This doesn't directly apply to time, as time doesn't directly count ticks, but scales them for you into real time in seconds, so +1 isn't quite right (you should add the quanta of the timer to the value), but it still has the advantage that it is a quick and dirty way to avoid the 0 duration, and after a human scale duration, doesn't perturb the value enough to make much of a difference. -- Richard Damon -- https://mail.python.org/mailman/listinfo/python-list
