def partitioner(self):
        return (self.options.partitioner or
                self.PARTITIONER or
                ('org.apache.hadoop.mapred.lib.KeyFieldBasedPartitioner' if
                 self.SORT_VALUES else None))

    ### Jobconf ###

    #: Optional jobconf arguments we should always pass to Hadoop. This
    #: is a map from property name to value. e.g.:
    #:
    #: ``{'stream.num.map.output.key.fields': '4'}``
    #:
    #: It's recommended that you only use this to hard-code things that
    #: affect the semantics of your job, and leave performance tweaks to
    #: the command line or whatever you use to launch your job.
Optional Hadoop partitioner class to use to determine how mapper
dataset/ETHPy150Open Yelp/mrjob/mrjob/job.py/MRJob.partitioner