Python memory handling

[Josh Bloom]

If the memory usage is that important to you, you could break this out
into 2 programs, one that starts the jobs when needed, the other that
does the processing and then quits.
As long as the python startup time isn't an issue for you.


On 31 May 2007 04:40:04 -0700, frederic.pica at gmail.com
<frederic.pica at gmail.com> wrote:
> Greets,
>
> I've some troubles getting my memory freed by python, how can I force
> it to release the memory ?
> I've tried del and gc.collect() with no success.
> Here is a code sample, parsing an XML file under linux python 2.4
> (same problem with windows 2.5, tried with the first example) :
> #Python interpreter memory usage : 1.1 Mb private, 1.4 Mb shared
> #Using http://www.pixelbeat.org/scripts/ps_mem.py to get memory
> information
> import cElementTree as ElementTree #meminfo: 2.3 Mb private, 1.6 Mb
> shared
> import gc #no memory change
>
> et=ElementTree.parse('primary.xml') #meminfo: 34.6 Mb private, 1.6 Mb
> shared
> del et #no memory change
> gc.collect() #no memory change
>
> So how can I free the 32.3 Mb taken by ElementTree ??
>
> The same problem here with a simple file.readlines()
> #Python interpreter memory usage : 1.1 Mb private, 1.4 Mb shared
> import gc #no memory change
> f=open('primary.xml') #no memory change
> data=f.readlines() #meminfo: 12 Mb private, 1.4 Mb shared
> del data #meminfo: 11.5 Mb private, 1.4 Mb shared
> gc.collect() # no memory change
>
> But works great with file.read() :
> #Python interpreter memory usage : 1.1 Mb private, 1.4 Mb shared
> import gc #no memory change
> f=open('primary.xml') #no memory change
> data=f.read() #meminfo: 7.3Mb private, 1.4 Mb shared
> del data #meminfo: 1.1 Mb private, 1.4 Mb shared
> gc.collect() # no memory change
>
> So as I can see, python maintain a memory pool for lists.
> In my first example, if I reparse the xml file, the memory doesn't
> grow very much (0.1 Mb precisely)
> So I think I'm right with the memory pool.
>
> But is there a way to force python to release this memory ?!
>
> Regards,
> FP
>
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>