On Jul 9, 7:48 am, "Rajanikanth Jammalamadaka" <[EMAIL PROTECTED]> wrote: > Try this: > > >>> li=[0,0,1,2,1,0,0] > >>> li > > [0, 0, 1, 2, 1, 0, 0]>>> [i for i in range(len(li)) if li[i] != 0] > > [2, 3, 4] > > Cheers, > > Raj > > > > On Tue, Jul 8, 2008 at 10:26 PM, Benjamin Goudey <[EMAIL PROTECTED]> wrote: > > I have a very large list of integers representing data needed for a > > histogram that I'm going to plot using pylab. However, most of these > > values (85%-95%) are zero and I would like to remove them to reduce > > the amount of memory I'm using and save time when it comes to plotting > > the data. To do this, I'm trying to find the best way to remove all of > > the zero values and produce a list of indices of where the non-zero > > values used to be. > > > For example, if my original list is [0,0,1,2,1,0,0] I would like to > > produce the lists [1,2,1] (the non zero values) and [2,3,4] (indices > > of where the non-zero values used to be). Removing non-zero values is > > very easy but determining the indicies is where I'm having difficulty. > > > Thanks in advance for any help > > -- > >http://mail.python.org/mailman/listinfo/python-list > > -- > "For him who has conquered the mind, the mind is the best of friends; > but for one who has failed to do so, his very mind will be the > greatest enemy." > > Rajanikanth
Whoops, misread the question li =[0,0,1,2,1,0,0] [(index,data) for index,data in enumerate(li) if data] -- http://mail.python.org/mailman/listinfo/python-list
