pyspark.RDD.sample

RDD.sample(withReplacement: bool, fraction: float, seed: Optional[int] = None) → pyspark.rdd.RDD[T]

Return a sampled subset of this RDD.

New in version 0.7.0.

Parameters

withReplacementbool

can elements be sampled multiple times (replaced when sampled out)

fractionfloat

expected size of the sample as a fraction of this RDD’s size without replacement: probability that each element is chosen; fraction must be [0, 1] with replacement: expected number of times each element is chosen; fraction must be >= 0

seedint, optional

seed for the random number generator

Returns

RDD

a new RDD containing a sampled subset of elements

See also

RDD.takeSample()

RDD.sampleByKey()

pyspark.sql.DataFrame.sample()

Notes

This is not guaranteed to provide exactly the fraction specified of the total count of the given DataFrame.

Examples

>>> rdd = sc.parallelize(range(100), 4)
>>> 6 <= rdd.sample(False, 0.1, 81).count() <= 14
True

pyspark.RDD.rightOuterJoin pyspark.RDD.sampleByKey