http://code.activestate.com/recipes/578375-proof-of-concept-for-a-more-space-efficient-faster/?in=user-178123
-- Dhruv Baldawa (http://www.dhruvb.com) On Thu, Apr 18, 2013 at 2:31 PM, Rahul R <rahul8...@gmail.com> wrote: > Afaik, python gc is threshold based. So, gc should trigger after a given > threshold value (which can be changed) . but defintely the code is worth > looking. thanks for pointing it out. > > ./Rahul > > On Thu, Apr 18, 2013 at 2:15 PM, Hrishikesh Kulkarni > <ri...@turtleyogi.com>wrote: > > > 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 > > > _______________________________________________ > 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
