On Fri, 05 Jul 2013 15:47:45 +0000, Helmut Jarausch wrote: > > for r, row_lst in enumerate(Grid): > > for c, val in enumerate(row_lst): > > I assume the creation of the temporary lists "row_list" is a bit > expensive. No temporary list is being created. The pre-existing list is just being grabbed, which is fast. -- Steven