timecheck.py

from datetime import datetime

tic_total = datetime.now()
tic = datetime.now()
print ("START")
while True:
    toc_total = (datetime.now()-tic_total).total_seconds()
    toc = (datetime.now()-tic).total_seconds()
    tic = datetime.now()
    if toc > 0.1:
        print ("[%.3fsec] diff:[%.3fsec]" % (toc_total,toc))
    if toc_total > 200:
        break
print ("DONE")