Allow sleeping until an absolute time

I propose a version of time.sleep() that allows for the specification of absolute times.

Python 3.11 added the use of clock_nanosleep in time.sleep() (#28111), and both it and Windows' SetWaitableTimerEx allow for the specification of absolute times. This can be useful for writing simple loops that trigger at an interval that is tied to wall-clock time, which has many applications: triggering taking of measurements, pictures, checking status, sending messages, ...

With time.sleep(), one has to emulate this by saying time.sleep(deadline - time.time()), which pysleep then calculates back into an absolute time internally, which adds inaccuracy.

I will be submitting a pull request shortly that modifies pysleep to give it an "absolute" argument and adds a time.sleep_until() function.

Linked PRs

• gh-101559