[Tutor] Releasing a File for Access

[Alan Gauld]

"Wayne Watson" <sierra_mtnview at sbcglobal.net> wrote 

> I need to use something like sys.exit(). 

sys.exit won't change the file permissions etc. 
It simply sets the exit status of the program.

I suspect the problem is that you still have IDLE running.
Have you tried testing the program outside IDLE? You might 
find it works OK there.

Also have you checked your file permissions? You may 
need to change the default settings using the os module.

> However, I'm in development mode right now with IDLE, 
> and there's a small penalty for using it with IDLE. 

The "penalty" is actually a benefit since having to restart 
IDLE and reload your working files each time you run your 
code is much less convenient than clicking a dialog button! :-)

> Although I user might try to rename  500 files at a single shot. 

I assume you are intending enhancing the program to accept 
multiple ufilenames?

>      def modify_txt_file(old_fname, new_event_date):
>          old_prefix = old_fname[0:19]

You might want to use os.basename() here as a more 
reliable way of extracting the extension.

>          input_file=open(old_fname,'r')
>          output_file=open(old_prefix+'.tmp','w')

>          print "modified txt file with event info"
>          # now copy tmp back to ...

And you might want to use os.remove() and os.rename() 
to do the final copy of the tmp file back to the original.

Just some thoughts

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld