pyspark.RDD.top#

RDD.top(num, key=None)[source]#

Get the top N elements from an RDD.

Added in version 1.0.0.

Parameters:

numint: top N
keyfunction, optional: a function used to generate key for comparing

Returns:

list: the top N elements

See also

RDD.takeOrdered()
RDD.max()
RDD.min()

Notes

This method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver’s memory.

It returns the list sorted in descending order.

Examples

>>> sc.parallelize([10, 4, 2, 12, 3]).top(1)
[12]
>>> sc.parallelize([2, 3, 4, 5, 6], 2).top(2)
[6, 5]
>>> sc.parallelize([10, 4, 2, 12, 3]).top(3, key=str)
[4, 3, 2]