qi clock API ¶
Libqi provides C++ types to model clocks, time points and durations. See qi clocks for an overview of the clocks.
The functions to get the current time of these clocks are also available in python. They return an integer number of nanoseconds.
You can use
as a substitute for python’s
import qi import time fmt = "%a, %d %b %Y %H:%M:%S +0000" t_sec = time.time() # floating point print("current local time is: " + time.ctime(t_sec)) t_nsec = qi.systemClockNow() # integer t_sec = t_nsec * 1e-9 # floating point print("current local time is: " + time.ctime(t_sec))
is mostly used for system-wide timestamps.
Sometimes, you may need the timestamp as a pair of integers,
counting seconds and microseconds, respectively. This can be done with:
import qi t_usec = qi.clockNow()/1000 timestamp = [t_usec/1000000, t_usec % 1000000]
is useful when one needs to measure durations
while being robust to system clock changes, as in
import qi import time t0_msec = qi.steadyClockNow()/1000000 time.sleep(0.5) t1_msec = qi.steadyClockNow()/1000000 print("I slept during " + str(t1_msec - t0_msec) + " milliseconds")
systemClockNow( ) → Int
Returns: current timestamp on qi::SystemClock, as a number of nanoseconds