code: def fix_opcode_names(opmap):
      
      return dict([(k.replace('+', '_'), v)
                    for (k, v) in opmap.items()])
docs: Python stupidly named some OPCODES with a + which prevents using opcode name
      directly as an attribute, e.g. SLICE+3. So we turn that into SLICE_3 so we
      can then use opcode_23.SLICE_3.  Later Python's fix this.