1 l = (1, 2, 3, "four") 2 print len(l) # 4 3 print l[0] # 1 4 print l[1] # 2 5 print l[2] # 3 6 print l[3] # four 7 print l[-1] # four 8 print l[-2] # 3 9 print l[-3] # 2 10 print l[-4] # 1 11 print l # (1, 2, 3, "four") 12 13 l = [1, 2, 3, "four"] 14 t = tuple(l) 15 print t # (1, 2, 3, "four") 16 17 try: 18 print t[4] # should raise an exception 19 except IndexError, exc: 20 print "t[4]: failed with argument", exc.index 21 22 try: 23 print t[-5] # should raise an exception 24 except IndexError, exc: 25 print "t[-5]: failed with argument", exc.index 26 27 a, b, c, d = l 28 print a, b, c, d # 1 2 3 "four" 29 30 try: 31 a, b, c = l 32 except ValueError, exc: 33 print "a, b, c = l: failed with length", exc.value