Python Programming Language :: Periodic tasks.


	Periodic tasks. Hi, I am trying to execute some tasks periodically, those familiar with unix can think of it as equivalent to cron jobs. I have tried looking around, but couldn't find a way. Would appreciate any pointers or clues.. Thanks, -Ram Ramashish Baranwal <ramashish.li@gmail.com> writes: > I am trying to execute some tasks periodically, those familiar with > unix can think of it as equivalent to cron jobs. Can you not use cron? If not, why not? Is there an equivalent service you can use? > I have tried looking around, but couldn't find a way. Using the services provided by the operating system would be far preferable to re-inventing a scheduler service. -- \ Contentsofsignaturemaysettleduringshipping. \| `\ \| _o__) \| Ben Finney > > I am trying to execute some tasks periodically, those familiar with > > unix can think of it as equivalent to cron jobs. > Can you not use cron? If not, why not? Is there an equivalent service > you can use? I can, but the work I want to do is written in Python. This is not an issue but I would have more than one such tasks running at different periods and it will be desirable to control or monitor all of them from a single process. If I use cron, all of them will execute independently. > > I have tried looking around, but couldn't find a way. > Using the services provided by the operating system would be far > preferable to re-inventing a scheduler service. Agreed, but my requirement is a little different. There is a TaskKit package (http://webware.sourceforge.net/Webware-0.7/TaskKit/Docs/ QuickStart.html) that has such a scheduler. Does anyone have any experience with it? Ram --- Ramashish Baranwal <ramashish.li@gmail.com> wrote: > Hi, > I am trying to execute some tasks periodically, > those familiar with > unix can think of it as equivalent to cron jobs. I > have tried looking > around, but couldn't find a way. Would appreciate > any pointers or > clues.. I'm also interested in this. On the assumption that you can't find a cron replacement in your OS, or that maybe you need a Python-written cron to do something a little different than cron, these are some things to look at: open(fn).readlines() line.split(' ', 6) time.sleep(), time.time() and other methods os.popen.readlines() (but others may disagree) In my case I need to run jobs periodically, but before running jobs, but I need to configure the times that the jobs run using a database, and I need to check on the status of the previous day's job, make sure that I'm running on the primary box, etc. Another technique people use is to use cron() and make it the responsibility of the scheduled programs to check that they should really proceed, and if there's a chance of overlapping with a previous job that's still running, you can use a file-locking scheme. ___________________________________________________________________________ _________ Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html Ben Finney wrote: > Ramashish Baranwal <ramashish.li@gmail.com> writes: >> I am trying to execute some tasks periodically, those familiar with >> unix can think of it as equivalent to cron jobs. > Can you not use cron? If not, why not? Is there an equivalent service > you can use? >> I have tried looking around, but couldn't find a way. > Using the services provided by the operating system would be far > preferable to re-inventing a scheduler service. Alternatively, the user could make use of the already-existing "sched" module from the standard library. With a little threading that would do the job fine. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden ------------------ Asciimercial --------------------- Get on the web: Blog, lens and tag your way to fame!! holdenweb.blogspot.com squidoo.com/pythonology tagged items: del.icio.us/steve.holden/python All these services currently offer free registration! -------------- Thank You for Reading ---------------- On May 29, 4:39 pm, Steve Holden <s@holdenweb.com> wrote: > Alternatively, the user could make use of the already-existing "sched" > module from the standard library. With a little threading that would do > the job fine. > regards > Steve > -- > Steve Holden +1 571 484 6266 +1 800 494 3119 > Holden Web LLC/Ltd http://www.holdenweb.com > Skype: holdenweb http://del.icio.us/steve.holden > ------------------ Asciimercial --------------------- Yes. Also, there's an example in the Python Cookbook (print edition) which is exactly about this - using sched. The recipe before that also shows how to do it without using the sched library. Both those recipes are purely in Python. Vasudev Ram Dancing Bison Enterprises www.dancingbison.com - Hide quoted text - --- vasudevram <vasudev@gmail.com> wrote: > On May 29, 4:39 pm, Steve Holden > <s@holdenweb.com> wrote: > > Alternatively, the user could make use of the > already-existing "sched" > > module from the standard library. With a little > threading that would do > > the job fine. > Yes. Also, there's an example in the Python Cookbook > (print edition) > which is exactly about this - using sched. The > recipe before that also > shows how to do it without using the sched library. > Both those recipes > are purely in Python. Thanks. Here are two links, not sure those are exactly what are being referenced here, but look in the ballpark: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/413137 http://docs.python.org/lib/module-sched.html ___________________________________________________________________________ _________Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase. http://farechase.yahoo.com/ Ramashish Baranwal wrote: > Hi, > I am trying to execute some tasks periodically, those familiar with > unix can think of it as equivalent to cron jobs. I have tried looking > around, but couldn't find a way. Would appreciate any pointers or > clues.. > Thanks, > -Ram Have a look at Kronos, a simple task scheduler I wrote a while ago, based on sched. It's part of Turbogears as well: http://trac.turbogears.org/browser/trunk/turbogears/scheduler.py --Irmen Steve Howell wrote: >Thanks. Here are two links, not sure those are >exactly what are being referenced here, but look in >the ballpark: > http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/413137 > http://docs.python.org/lib/module-sched.html You're welcome. The ActiveState recipe you mention above is not the one I meant, although it uses sched. I saw the recipe that I mentioned, in the print version of the Python Cookbook, when reading it a few days ago. The second link above you mention is right, its about the sched library. Also just found these other recipes in the online Python Cookbook, may or may not be of help to you: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/496800 http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/114644 Vasudev Ram www.dancingbison.com On May 29, 2:33 pm, Ramashish Baranwal <ramashish.li@gmail.com> wrote: > Hi, > I am trying to execute some tasks periodically, those familiar with > unix can think of it as equivalent to cron jobs. I have tried looking > around, but couldn't find a way. Would appreciate any pointers or > clues.. > Thanks, > -Ram I googled "twisted cron", if u use twisted, that's maybe help u: http://svn.zope.org/Zope3/trunk/src/scheduler/cron.py?rev=38967&view=... http://twistedmatrix.com/pipermail/twisted-python/2006-June/013525.html