Best way to capture short spans in a Duration?

[Evan0000000000]

i was to measure execution time with perfcounter and convert that to a Duration to take advantage of the attributes in formatting a logging message.

It seems like to do this one has to do roughly:

start = perfcounter()
# run some stuff that takes time
elapsed = perfcounter() - start

elapsed_msec, elapsed_sec = math.modf(elapsed)
elapsed_msec = elapsed_msec * 100 

elapsed_d= Duration(seconds=elapsed_sec, milliseconds=elapsed_msec) 
log.info(f'Elapsed time: {elapsed_d.hours}:'
                            f'{elapsed_d.minutes}:'
                            f'{elapsed_d.remaining_seconds}'
                            )

This seems a little convoluted, but conversely using Datetime.now() doesn't capture any time elapsed for relatively fast intervals, so I'm not sure of a better way to achieve this.

Edit-
For context this is for wrapping around some data processing functionality, so a large dataset may conceivably take a few hours but a test case or a small dataset may take virtually no time, hence the interest in easy access to the Duration's hour minute and second attributes while also capturing small spans of time as well.

[agammann]

You can pass the floating point elapsed seconds directly to pendulum.duration(). You do not need to split the integer and fractional parts:

import pendulum
from time import perf_counter

start = perf_counter()
# Run the work being measured here.
elapsed_d = pendulum.duration(seconds=perf_counter() - start)

print(
    f'{elapsed_d.in_hours()}:'
    f'{elapsed_d.minutes:02}:'
    f'{elapsed_d.remaining_seconds:02}.'
    f'{elapsed_d.microseconds:06}'
)

The fractional seconds are retained to microsecond precision. Including microseconds in the output matters for short operations: the hours, minutes, and whole seconds alone would all display zero. I used in_hours() so an elapsed time longer than a day shows total hours.

I tested Pendulum 3.2.0 with seconds=0.012345, which prints 0:00:00.012345, and seconds=3661.123456, which prints 1:01:01.123456. I also checked an actual perf_counter() measurement; the duration retained its elapsed value rounded to microseconds. perf_counter() is suitable for measuring elapsed time, and Duration accepts fractional seconds.