code: def run_mapper(self, stdin=sys.stdin, stdout=sys.stdout):
          
          self.init_hadoop()
          self.init_mapper()
          outputs = self._map_input((line[:-1] for line in stdin))
          if self.reducer == NotImplemented:
              self.writer(outputs, stdout)
          else:
              self.internal_writer(outputs, stdout)
docs: Run the mapper on the hadoop node.