code: def gpg_interactive_input(self, sub_keys_number):
          
          deselect_sub_key = "key 0\n"
  
          _input = self._main_key_command()
          for sub_key_number in range(1, sub_keys_number + 1):
              _input += self._sub_key_command(sub_key_number) + deselect_sub_key
          return "%ssave\n" % _input
docs: processes series of inputs normally supplied on --edit-key but passed through stdin
              this ensures that no other --edit-key command is actually passing through.