[Tutor] Closeing a file written to by cPickle dump

[Liam Clarke]

Hi all, 

Pickle... just reading O'Reilly's Python In A Nutshell, and thought
this would be an opportune time to clarify pickling. Pickle will write
dictionaries/classes/functions to disk, and then read them back in a
usable manner? I'm just trying to paraphrase this module's
functionality, as O'Reilly states -

"The pickle and cPickle modules supply factory functions, named
Pickler and Unpickler, to generate objects that wrap file-like objects
and supply serialization mechanisms."

Which makes me say 'Wuzzah?'
If so, how silly am I, creating functions to load/save dictionaries
myself, when there already exists functions to do that, plus save
other useful stuff.

Regards,

Liam Clarke


On Sat, 27 Nov 2004 16:13:31 -0500, Kent Johnson <kent37 at tds.net> wrote:
> Dave S wrote:
> > I need to use pickle to save dictionaries, I have started:
> >
> > .....
> > from cPickle import dump
> > ......
> > dump(dict,open(data_dir+'/'+save_name,'w'))
> >
> > It appears to work OK & I can read from the pickle but in this dump
> > format do I need to close the open file with an equiverlant of
> > xxx.close(). Am I in danger of data not being flushed to the hard drive ?
> 
> Though it may not always be necessary,  I think it is prudent to always
> close a file that was opened for writing. The call to open returns a
> file object, you just have to retain a reference to it so you can close
> it when you are done:
> 
> f=open(data_dir+'/'+save_name,'w'
> dump(dict,f))
> f.close()
> 
> 
> 
> >
> > If I do need to close it, how do I do that because there is no class
> > instance ?
> >
> > Cheers
> > Dave
> >
> >
> > _______________________________________________
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> > http://mail.python.org/mailman/listinfo/tutor
> >
> _______________________________________________
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> 


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