[Tutor] MemoryError

[Liam Clarke]

Oh, and I never knew about .read() for a file object. I always just
used readline/readlines. Silly, really.



On Thu, 9 Dec 2004 11:31:40 +1300, Liam Clarke <cyresse at gmail.com> wrote:
> > I'm not sure why you're getting the MemoryError, but it'd be easier to
> > figure out if you posted the entire text of the traceback.
> 
> 
> Traceback: <usual bit about in module..>
> 
> Line 39: seg=codeSt[element:endInd+len(endStr]
> MemoryError
> 
> Hehe. Helpful, no?
> 
> I think I'll sprinkle print statements throughout as suggested, and
> wrap it in a function for that optimization Jeff mentioned.
> 
> Thanks for the advice, I'll let you know how it goes.
> 
> Regards,
> 
> Liam Clarke
> 
> I didn't think to
> 
> 
> On Wed, 08 Dec 2004 12:29:10 -0800, Jeff Shannon <jeff at ccvcorp.com> wrote:
> > Liam Clarke wrote:
> >
> > > Hi all,
> > >
> > > I'm playing with a file, and attempting to replace a section with a
> > > string, and using the following command -
> > >
> > > seg=codeSt[element:endInd+len(endStr]
> > > codeSt=codeSt.replace(seg, hrefString)
> > >
> > > At the replace, I get a MemoryError. It's part of a for loop, but it
> > > gives the error the first time around.
> >
> >
> > I'm not sure why you're getting the MemoryError, but it'd be easier to
> > figure out if you posted the entire text of the traceback.
> >
> > A few other pointers --
> >
> > You'll probably get better performance if you put all of this code
> > inside of a function.  Even if you're only running it once, putting it
> > in a function allows the interpreter to do some optimization tricks on
> > locals() which can't be done at the module-global level (where you're
> > running now).  It's just barely possible that just doing this will
> > help with your MemoryError problem.  (You would probably benefit from
> > splitting it into multiple functions, actually.  I'd have the code
> > that finds text and url values each in their own function, for example.)
> >
> > Try adding a line in between those two that prints out the value of
> > element and endInd, and then check that those numbers really are valid
> > indexes into codeSt.  While you're at it, print out hrefString and
> > make sure it looks like it's supposed to.
> >
> > At the start of your program, you have the following:
> >
> >      inp=file("toolkit.txt","r")
> >      codeSt=inp.readlines()
> >      inp.close()
> >      codeSt="".join(codeSt)
> >
> > Since you're not processing by lines, and are explicitly joining all
> > the lines together, why have Python separate them for you?  It would
> > be much more efficient to simply use 'codeSt = inp.read()', with no
> > need to join() afterwards.  The readlines() method effectively does a
> > read() followed by splitting the result into lines; for your purposes,
> > there's no point in splitting the lines if you're just going to join()
> > them immediately.
> >
> > Instead of finding the start and end index of the segment you want to
> > replace, making a copy of that segment, and then scanning your
> > original string to replace that segment with a new chunk, it would
> > probably make more sense to simply grab codeSt before the segment and
> > after the segment and concatenate them with the new chunk.  Thus, your
> > two lines above become
> >
> >      codeSt = codeSt[:element] + hrefString \
> >                       + codeSt[endInd+len(endStr)]
> >
> > Once again, this would avoid doing the same work twice.
> >
> > > Now, I had imagined that codeSt=codeSt+10 would destroy the old codeSt
> > > in memory and create a new codeSt. Am I right?
> >
> > Actually, this will probably raise a TypeError (cannot concatenate
> > 'str' and 'int' objects).  ;)  But yes, rebinding codeSt to a new
> > string should allow the old string to be destroyed (if there are no
> > other references to it).
> >
> > Hope that this helps.
> >
> > Jeff Shannon
> > Technician/Programmer
> > Credit International
> >
> >
> >
> >
> > _______________________________________________
> > Tutor maillist  -  Tutor at python.org
> > http://mail.python.org/mailman/listinfo/tutor
> >
> 
> --
> 'There is only one basic human right, and that is to do as you damn well please.
> And with it comes the only basic human duty, to take the consequences.
> 


-- 
'There is only one basic human right, and that is to do as you damn well please.
And with it comes the only basic human duty, to take the consequences.