crython
crython is a lightweight task (function) scheduler using cron expressions written in python.
Status
This module is actively maintained.
Installation
To install crython from pip:
$ pip install crythonTo install crython from source:
$ git clone [email protected]:ahawker/crython.git
$ python setup.py installUsage
Crython supports seven fields (seconds, minutes, hours, day of month, month, weekday, year).
Call a function once a minute:
import crython
# Fire once a minute.
@crython.job(second=0)
def foo():
print "... while heavy sack beatings are up a shocking nine hundred percent? - Kent Brockman"Call a function every ten seconds:
# Fire every 10 seconds.
@crython.job(second=range(0, 60, 10))
def foo():
print "I'm a big four-eyed lame-o and I wear the same stupid sweater every day. - Homer's Brain"Call a function with a single cron expression:
# Fire every 10 seconds.
@crython.job(second='*/10')
def foo():
print "Hail to the thee Kamp Krusty... - Kampers"Call a function with a full cron expression:
# Fire once a week.
@crython.job(expr='0 0 0 * * 0 *')
def foo():
print "Back in line, maggot! - Kearny"Call a function with positional and/or keyword arguments:
# Fire every second.
@job('safety gloves', second='*', name='Homer Simpson')
def foo(item, name):
print "Well, I don't need {0}, because I'm {1}. -- Grimey".format(item, name)Call a function using predefined keywords:
# Fire once a day.
@crython.job(expr='@daily')
def foo():
print "That's where I saw the leprechaun. He tells me to burn things! - Ralph Wiggum" # Fire once immediately after scheduler starts.
@crython.job(expr='@reboot')
def foo():
print "I call the big one bitey. - Homer Simpson"Call a function and run it within a separate thread (default behaviour if ctx is not specified):
# Fire once a week.
@crython.job(expr='@weekly', ctx='thread')
def foo():
print "No, no, dig up stupid. - Chief Wiggum"Call a function and run it within a separate process:
# Fire every hour.
@crython.job(expr='@hourly', ctx='multiprocess')
def foo():
print "Eat my shorts. - Bart Simpson"Start the global job scheduler:
if __name__ == '__main__':
crython.start()
crython.join() ## This will blockStop the global job scheduler:
crython.stop()
crython.join(timeout=5000) ## This will block 5s waiting for thread to stop.Keywords
| Entry | Description | Equivalent To |
|---|---|---|
| @yearly/@annually | Run once a year at midnight in the morning of January 1 | 0 0 0 0 1 1 * |
| @monthly | Run once a month at midnight in the morning of the first of the month | 0 0 0 0 1 * * |
| @weekly | Run once a week at midnight in the morning of Sunday | 0 0 0 0 * 0 * |
| @daily | Run once a day at midnight | 0 0 0 * * * * |
| @hourly | Run once an hour at the beginning of the hour | 0 0 * * * * * |
| @minutely | Run once a minute at the beginning of the minute | 0 * * * * * * |
| @reboot | Run once at startup | @reboot |
TODO
- Support "L", "W" and "#" specials.
- Determine time delta from now -> next time expression is valid.
Contributing
If you would like to contribute, simply fork the repository, push your changes and send a pull request.
License
Crython is available under the MIT license.
See Other
There are similar python cron libraries out there. See: pycron, python-crontab, cronex.