Why they use this: duration = time.time() - self.start_time + 1
Cameron Simpson
cs at cskk.id.au
Sat Aug 3 22:44:52 EDT 2019
On 04Aug2019 02:33, Hongyi Zhao <hongyi.zhao at gmail.com> wrote:
>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
This is almost certainly because they divide by duration on the next
line. By adding 1, duration will never be 0.
This code does assume that time.time() never goes backwards, which is
usually true. However, the system clock can be adjusted, and might go
backwards.
My personal habit in this circumstance is to compare the duration with 0
and avoid the division if so; I'd return speed=None in that circumstance
because I cannot yet compute it. Interestingly you can see that they do
exactly that logical shuffle on line 248 with the speed. You might
expect they would do the same for duration but they do not.
Cheers,
Cameron Simpson <cs at cskk.id.au>
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