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From: Wong Wah Meng-R32813 <r32813@freescale.com>
To: Steven D'Aprano <steve+comp.lang.python@pearwood.info>, "python-list@python.org" <python-list@python.org>
Subject: RE: Set x to  to None and del x doesn't release memory in python 2.7.1	(HPUX 11.23, ia64)
Thread-Topic: Set x to  to None and del x doesn't release memory in python 2.7.1	(HPUX 11.23, ia64)
Thread-Index: AQHOGsPNVeasEGmgzUia3vP4E6GnC5iZxOCw
Date: Thu, 7 Mar 2013 06:33:23 +0000
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Xref: csiph.com comp.lang.python:40710

Python does not guarantee to return memory to the operating system.=20
Whether it does or not depends on the OS, but as a general rule, you should=
 expect that it will not.


>>>> for i in range(100000L):
> ...     str=3Dstr+"%s"%(i,)


You should never build large strings in that way. It risks being=20
horribly, horribly slow on some combinations of OS, Python implementation=20
and version.

Instead, you should do this:

items =3D ["%s" % i for i in range(100000)]
s =3D ''.join(items)

[] The example is written for illustration purpose. Thanks for pointing out=
 a better way of achieving the same result. Yes it seems so that the OS thi=
nks the piece allocated to Python should not be taken back unless the proce=
ss dies. :(