print('( ab to moves disk from tower to tower )' response input(''upper(strip( if response ='quit' print('thanks for playing!' sys exit( make sure the user entered valid tower letters if response not in ('ab''ac''ba''bc''ca''cb') print('enter one of abacbabccaor cb ' continue ask player again for their move syntactic sugar use more descriptive variable names fromtowertotower response[ ]response[ if len(towers[fromtower]= the "fromtower cannot be an empty tower print('you selected tower with no disks ' continue ask player again for their move elif len(towers[totower]= any disk can be moved onto an empty "totower return fromtowertotower elif towers[totower][- towers[fromtower][- ] print('can\' put larger disks on top of smaller ones ' continue ask player again for their move else this is valid moveso return the selected towers return fromtowertotower def displaytowers(towers) """display the current state "" display the three towers for level in range(total_disks- - ) for tower in (towers[' ']towers[' ']towers[' ']) if level >len(tower) displaydisk( display the bare pole with no disk else displaydisk(tower[level]display the disk print( display the tower labels aband emptyspace (total_disks print('{ { }{ { }{ \nformat(emptyspace) def displaydisk(width) """display disk of the given width width of means no disk "" emptyspace (total_disks width if width = display pole segment without disk print(emptyspace '||emptyspaceend='' else project #