The code snippet shows the old_value and old_keys are marked by decref not the dummy. I wouldnt worry about dummy keys so much. btw checkout dictresize which is called during insert/set which does resize the dict. When? that would be a good learning exercise.
On Thu, Apr 18, 2013 at 2:09 PM, Rahul R <rahul8...@gmail.com> wrote: > Hey Hrishikesk, > > So are you saying, if i run gc.collect() in my program I will get rid of > all the dummy variables in the dictionary ? > > Thanks, > ./Rahul > > On Thu, Apr 18, 2013 at 12:06 PM, Hrishikesh Kulkarni > <ri...@turtleyogi.com>wrote: > > > 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 > > > > > > > _______________________________________________ > > > > > > > BangPypers mailing list > > > > > > > BangPypers@python.org > > > > > > > http://mail.python.org/mailman/listinfo/bangpypers > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > Anand > > > > > > http://anandology.com/ > > > > > > _______________________________________________ > > > > > > BangPypers mailing list > > > > > > BangPypers@python.org > > > > > > http://mail.python.org/mailman/listinfo/bangpypers > > > > > > > > > > > _______________________________________________ > > > > > BangPypers mailing list > > > > > BangPypers@python.org > > > > > http://mail.python.org/mailman/listinfo/bangpypers > > > > > > > > > > > > > > > > > > > > > -- > > > > Ramdas S > > > > +91 9342 583 065 > > > > My Personal Blog on http://ramdaz.wordpress.com > > > > _______________________________________________ > > > > BangPypers mailing list > > > > BangPypers@python.org > > > > http://mail.python.org/mailman/listinfo/bangpypers > > > > > > > _______________________________________________ > > > BangPypers mailing list > > > BangPypers@python.org > > > http://mail.python.org/mailman/listinfo/bangpypers > > > > > _______________________________________________ > > BangPypers mailing list > > BangPypers@python.org > > http://mail.python.org/mailman/listinfo/bangpypers > > > _______________________________________________ > BangPypers mailing list > BangPypers@python.org > http://mail.python.org/mailman/listinfo/bangpypers > _______________________________________________ BangPypers mailing list BangPypers@python.org http://mail.python.org/mailman/listinfo/bangpypers
