dis s3f SETUP_LOOP 32 to 35 LOAD_GLOBAL enumerate LOAD_GLOBAL lst CALL

>>> dis(s3f)
  2           0 SETUP_LOOP              32 (to 35)
              3 LOAD_GLOBAL              0 (enumerate)
              6 LOAD_GLOBAL              1 (lst)
              9 CALL_FUNCTION            1
             12 GET_ITER            
        >>   13 FOR_ITER                18 (to 34)
             16 UNPACK_SEQUENCE          2
             19 STORE_FAST               0 (i)
             22 STORE_FAST               1 (v)

  3          25 LOAD_FAST                1 (v)
             28 STORE_FAST               2 (elem)
             31 JUMP_ABSOLUTE           13
        >>   34 POP_BLOCK           
        >>   35 LOAD_CONST               0 (None)
             38 RETURN_VALUE        
>>>