storing variable value

Daniel Dalton d.dalton at iinet.net.au
Tue Apr 14 05:34:39 CEST 2009


Yes. I used a file, thanks.


On Sat, Apr 11, 2009 at 09:30:40AM -0400, Dave Angel wrote:
>
>
> Daniel Dalton wrote:
>> Hi!
>>
>> I'm writing a program to provide me with battery warnings when my
>> battery hits certain levels. It just checks the current level and does
>> something. I plan to call it from a a cron job. But If the cron runs
>> every minute, warnings every minute would be rather annoying. so is
>> there a way to make the script check if it has already ran before?
>> eg. can I write to a variable on one run of the program, and on the next
>> read that value that was written?
>>
>> Thx!
>>
>> Daniel.
>>
>>   
> To put it simply, you want to store a value from one run of the script,  
> that persists till the next run of the same script.
>
> The most portable way to to that is to write a file.  And since all you  
> care about is the time of writing, the file can be zero length.  So  
> simply check for the file, determine it's creation time, and decide if  
> it's too recent to want to run again.  If the file doesn't exist, or is  
> "old", then write the file and notify the user.
>
>
> It's still messy to leave this bogus file around, so think carefully  
> about where to put it.  If the source directory is writable, it's  
> reasonble to me to simply put it there.  That way, if the program gets  
> deleted, it'll probably get deleted at the same time.  Failing that, you  
> could put it in a TEMP directory.  And perhaps the sneakiest place to  
> put it, if you're on Windows, is in the "run once on startup" directory.  
> Make it a do-nothing batch file, and Windows will remove it next time the 
> user restarts the system.
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
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