Parsing crontab-style lines

Question

I need to parse a crontab-like schedule definition in Python (e.g. 00 3 * * *) and get where this should have last run.

Is there a good (preferably small) library that parses these strings and translates them to dates?

Answer 1

Perhaps the python package croniter suits your needs.

Usage example:

>>> import croniter
>>> import datetime
>>> now = datetime.datetime.now()
>>> cron = croniter.croniter('45 17 */2  * *', now)
>>> cron.get_next(datetime.datetime)
datetime.datetime(2011, 9, 14, 17, 45)
>>> cron.get_next(datetime.datetime)
datetime.datetime(2011, 9, 16, 17, 45)
>>> cron.get_next(datetime.datetime)
datetime.datetime(2011, 9, 18, 17, 45)

Answer 2

Maybe you can use this module:

http://code.activestate.com/recipes/577466-cron-like-triggers/

I used that module for making an user-space cron in Python and it works very well. This module can handle crontab-like lines.