memory recycling/garbage collecting problem

[Tim Wintle]

On Tue, 2009-02-17 at 00:40 -0800, Chris Rebert wrote: 
> >
> > 'gc.collect()' -- I believe, but I'm not the specialist in it.
> 
> If I understand correctly, that only effects objects that are part of
> a reference cycle and doesn't necessarily force the freed memory to be
> released to the OS.

I believe that's correct.

If the OP is worrying about memory usage then they should also be aware
that there are lots of very clever things done pre-assigning and keeping
hold of memory with python's in-built types to let them scale well that
can be confusing when you're looking at memory usage.

Basically malloc() and free() are computationally expensive, so Python
tries to call them as little as possible - but it's quite clever at
knowing what to do - e.g. if a list has already grown large then python
assumes it might grow large again and keeps hold of a percentage of the
memory.

The outcome is that trying to reduce memory usage can change what data
structures you should use - tupples use less space than lists, etc.

Tim W