A bit of fun with a sleepy generator.
The question is about time delay. It can be fixed time, but in some cases we might need a delay measured since last time. Here is one possible solution:
The situation can be, we want to do something as regularly as possible and we do not want to bother with all the last_time
, next_time
stuff all around our code.
The following code (sleepy.py) defines a buzzergen
generator:
import time
from itertools import count
def buzzergen(period):
nexttime = time.time() + period
for i in count():
now = time.time()
tosleep = nexttime - now
if tosleep > 0:
time.sleep(tosleep)
nexttime += period
else:
nexttime = now + period
yield i, nexttime
from sleepy import buzzergen
import time
buzzer = buzzergen(3) # Planning to wake up each 3 seconds
print time.time()
buzzer.next()
print time.time()
time.sleep(2)
buzzer.next()
print time.time()
time.sleep(5) # Sleeping a bit longer than usually
buzzer.next()
print time.time()
buzzer.next()
print time.time()
And running it we see:
1400102636.46
1400102639.46
1400102642.46
1400102647.47
1400102650.47
We can also use it directly in a loop:
import random
for ring in buzzergen(3):
print "now", time.time()
print "ring", ring
time.sleep(random.choice([0, 2, 4, 6]))
And running it we might see:
now 1400102751.46
ring (0, 1400102754.461676)
now 1400102754.46
ring (1, 1400102757.461676)
now 1400102757.46
ring (2, 1400102760.461676)
now 1400102760.46
ring (3, 1400102763.461676)
now 1400102766.47
ring (4, 1400102769.47115)
now 1400102769.47
ring (5, 1400102772.47115)
now 1400102772.47
ring (6, 1400102775.47115)
now 1400102775.47
ring (7, 1400102778.47115)
As we see, this buzzer is not too rigid and allow us to catch up with regular sleepy intervals even if we oversleep and get out of regular schedule.