On Wed, Jan 9, 2013 at 11:19 AM, <andydtay...@gmail.com> wrote: > stn_count = len(stn_list_short) > for rowcount in range (0, stn_count): > for colcount in range (0, stn_count): > print stn_list_long[rowcount] stn_list_long[colcount]
First off, you can iterate over the list directly: for row in stn_list_short: for col in stn_list_short: print row + col (I'm not sure what your code was doing with the print line, because it ought to have failed. Explicit concatenation will work.) Secondly, you can make a list of all of those pairs with a compact notation called a comprehension: pairs = [row + col for row in stn_list_short for col in stn_list_short] That covers your requirement #2, giving you a full list of all of them. How big is k going to be? Storing the whole list in memory will get a little awkward if you have very large k; on this system, I started seeing performance issues with a thousand elements in the list, but you could probably go to ten thousand (ie a hundred million pairs) if you have a decent bit of RAM. ChrisA -- http://mail.python.org/mailman/listinfo/python-list