On Jul 29, 3:59 am, John Machin <[EMAIL PROTECTED]> wrote: > On Jul 29, 8:10 am, John Krukoff <[EMAIL PROTECTED]> wrote: > > > > > > > On Mon, 2008-07-28 at 16:24 -0500, Ervan Ensis wrote: > > > My programming skills are pretty rusty and I'm just learning Python so > > > this problem is giving me trouble. > > > > I have a list like [108, 58, 68]. I want to return the sorted indices > > > of these items in the same order as the original list. So I should > > > return [2, 0, 1] > > > > For a list that's already in order, I'll just return the indices, i.e. > > > [56, 66, 76] should return [0, 1, 2] > > > > Any help would be appreciated. > > > > -- > > >http://mail.python.org/mailman/listinfo/python-list > > > If your lists aren't so large that memory is an issue, this might be a > > good place for a variation of decorate, sort, undecorate. > > > >>> listToSort = [ 108, 58, 68 ] > > >>> decorated = [ ( data, index ) for index, data in > > > enumerate( listToSort ) ]>>> decorated > > > [(108, 0), (58, 1), (68, 2)]>>> result = [ None, ] * len( listToSort ) > > >>> for sortedIndex, ( ignoredValue, originalIndex ) in > > > enumerate( sorted( decorated ) ): > > ... result[ originalIndex ] = sortedIndex > > ...>>> result > > > [2, 0, 1] > > Simpliciter: > > > > >>> data = [99, 88, 77, 88, 66] > >>> [x[1] for x in sorted(zip(data, xrange(len(data))))] > [4, 2, 1, 3, 0] > > Use case? Think data == database table, result == index ...- Hide quoted text > - > > - Show quoted text -
I think it is wrong, using this on my data returns the wrong result data = [108, 58, 68, 108] >>> [x[1] for x in sorted(zip(data, xrange(len(data))))] [1, 2, 0, 3] -- http://mail.python.org/mailman/listinfo/python-list
