Please put some light on why am getting a too many to unpack (ValueError in my for loop).Have tried deb

 naislist = [('CONTROL FILE', '0', '0', '0'),
            ('REDO LOG', '0', '0', '0'),
            ('ARCHIVED LOG', '.69', '.59', '3'),
            ('BACKUP PIECE', '46.54', '0', '192'),
            ('IMAGE COPY', '0', '0', '0'),
            ('FLASHBACK LOG', '10.15', '6.31', '82'),
            ('FOREIGN ARCHIVED LOG', '0', '0', '0')]
 print "size of naislist is ",len((naislist))
 heading = ('MAIN MENU', 'LEVELS', 'LEVEL2', 'LEVEL3')

 rearrange = dict(zip((0, 1, 2, 3), (len(str(x)) for x in heading)))

 for tu, x in naislist:
     rearrange.update((i, max(rearrange[i], len(str(el))))  for i, el in enumerate(tu))
     rearrange[4] = max(rearrange[4], len(str(x)))
 forkit = '|'. join('%%-%ss' % rearrange[i] for i in xrange(0, 4))
 print '\n'.join((forkit % heading,
                  '-|-'.join(rearrange[i] * '-' for i in xrange(4)),
                  '\n'.join(forkit % (a, b, c, d) for (a, b, c), d in naislist)))