pyspark.RDD.mapPartitions

RDD.mapPartitions(f: Callable[[Iterable[T]], Iterable[U]], preservesPartitioning: bool = False) → pyspark.rdd.RDD[U][source]

Return a new RDD by applying a function to each partition of this RDD.

New in version 0.7.0.

Parameters
ffunction

a function to run on each partition of the RDD

preservesPartitioningbool, optional, default False

indicates whether the input function preserves the partitioner, which should be False unless this is a pair RDD and the input

Returns
RDD

a new RDD by applying a function to each partition

Examples

>>> rdd = sc.parallelize([1, 2, 3, 4], 2)
>>> def f(iterator): yield sum(iterator)
...
>>> rdd.mapPartitions(f).collect()
[3, 7]