On Wed, Apr 17, 2013 at 9:30 PM, Rahul R <rahul8...@gmail.com> wrote:
> As far as i know, python performs a lazy deletion of values , when we
> delete content from a dictionary (correct me if i am wrong) . So, when we
> insert a lot of values the dictionary automatically expands. I don't see
> dict shrinking when we delete values from dictionary. In such case, is
> there a way to forcibly reduce the dictionary size ?
>
Are you measuring this shrinking?
the following in dictobject.c should guide you with the internals. The
deleted item is simply replaced with a refcounted dummy. The deleted item
is marked for cleanup by gc with decref.
PyDict_DelItem () :
..
old_key = ep->me_key;
Py_INCREF(dummy);
ep->me_key = dummy;
old_value = ep->me_value;
ep->me_value = NULL;
mp->ma_used--;
Py_DECREF(old_value);
Py_DECREF(old_key);
..
dict_length():
..
return mp->ma_used;
..
PyDict_Size():
..
return ((PyDictObject *)mp)->ma_used;
..
regards,
Rishi
>
> ./Rahul
>
> On Wed, Apr 17, 2013 at 9:23 PM, Ramdas S <ram...@gmail.com> wrote:
>
> > On Wed, Apr 17, 2013 at 9:22 PM, Rahul R <rahul8...@gmail.com> wrote:
> >
> > > Ahh , sorry If i wasnt clear the first time. I dint mean reorder the
> data
> > > in dictionary. I meant resize the dictionary.
> > >
> >
> > What do you mean by resize?
> >
> >
> > >
> > > ./Rahul
> > >
> > > On Wed, Apr 17, 2013 at 9:05 PM, Anand Chitipothu <
> anandol...@gmail.com
> > > >wrote:
> > >
> > > > dictionaries are unordered. It is not a good idea to expect any order
> > in
> > > > dictionaries, even if you are seeing some order by chance.
> > > >
> > > > If you need order, then use OrderedDict from collections module (new
> in
> > > > Python 2.7).
> > > >
> > > > Anand
> > > >
> > > >
> > > > On Wed, Apr 17, 2013 at 9:00 PM, Rahul R <rahul8...@gmail.com>
> wrote:
> > > >
> > > > > Hey Guys,
> > > > >
> > > > > Is it possible to forcibly reorder the python dictionary after "n"
> > > number
> > > > > of inserts and deletions. As far as i know, python dictionary
> > performs
> > > > lazy
> > > > > deletes. Thus , even if the data is deleted, python has a dummy
> data
> > > > their
> > > > > in order to preserve consistency. The python dictionary
> > > > > keeps expanding when the size of dict is increasing, but after
> > > deleting a
> > > > > few parameters the size does not decrease. Is there a way , where I
> > can
> > > > > forcibly resize the dictionary ?
> > > > >
> > > > > I was thinking of copying content from existing dictionary to new
> > dict
> > > > and
> > > > > deleting the previous one.But thats a cumbersome operation.
> > > > >
> > > > > Thanks,
> > > > > ./Rahul
> > > > > _______________________________________________
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> > > >
> > > >
> > > >
> > > > --
> > > > Anand
> > > > http://anandology.com/
> > > > _______________________________________________
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> >
> >
> >
> > --
> > Ramdas S
> > +91 9342 583 065
> > My Personal Blog on http://ramdaz.wordpress.com
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