# pyspark.RDD.reduceByKeyLocally¶

RDD.reduceByKeyLocally(func)[source]

Merge the values for each key using an associative and commutative reduce function, but return the results immediately to the master as a dictionary.

This will also perform the merging locally on each mapper before sending results to a reducer, similarly to a “combiner” in MapReduce.

Examples

>>> from operator import add
>>> rdd = sc.parallelize([("a", 1), ("b", 1), ("a", 1)])