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# The ASF licenses this file to You under the Apache License, Version 2.0

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# http://www.apache.org/licenses/LICENSE-2.0

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"""

An example demonstrating PrefixSpan.

Run with:

bin/spark-submit examples/src/main/python/ml/prefixspan_example.py

"""

# $example on$

from pyspark.ml.fpm import PrefixSpan

# $example off$

from pyspark.sql import Row, SparkSession

if __name__ == "__main__":

spark = SparkSession\

.builder\

.appName("PrefixSpanExample")\

.getOrCreate()

sc = spark.sparkContext

# $example on$

df = sc.parallelize([Row(sequence=[[1, 2], [3]]),

Row(sequence=[[1], [3, 2], [1, 2]]),

Row(sequence=[[1, 2], [5]]),

Row(sequence=[[6]])]).toDF()

prefixSpan = PrefixSpan(minSupport=0.5, maxPatternLength=5,

maxLocalProjDBSize=32000000)

# Find frequent sequential patterns.

prefixSpan.findFrequentSequentialPatterns(df).show()

# $example off$

spark.stop()