code: def outputMode(self, outputMode):
          
          if not outputMode or type(outputMode) != str or len(outputMode.strip()) == 0:
              raise ValueError('The output mode must be a non-empty string. Got: %s' % outputMode)
          self._jwrite = self._jwrite.outputMode(outputMode)
          return self
docs: Specifies how data of a streaming DataFrame/Dataset is written to a streaming sink.
  
          Options include:
  
          * `append`:Only the new rows in the streaming DataFrame/Dataset will be written to
             the sink
          * `complete`:All the rows in the streaming DataFrame/Dataset will be written to the sink
             every time these is some updates
          * `update`:only the rows that were updated in the streaming DataFrame/Dataset will be
             written to the sink every time there are some updates. If the query doesn't contain
             aggregations, it will be equivalent to `append` mode.
  
         .. note:: Evolving.
  
          >>> writer = sdf.writeStream.outputMode('append')