examples/src/main/python/ml/tokenizer_example.py

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# 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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# $example on$
from pyspark.ml.feature import Tokenizer, RegexTokenizer
from pyspark.sql.functions import col, udf
from pyspark.sql.types import IntegerType
# $example off$
from pyspark.sql import SparkSession

if __name__ == "__main__":
    spark = SparkSession\
        .builder\
        .appName("TokenizerExample")\
        .getOrCreate()

    # $example on$
    sentenceDataFrame = spark.createDataFrame([
        (0, "Hi I heard about Spark"),
        (1, "I wish Java could use case classes"),
        (2, "Logistic,regression,models,are,neat")
    ], ["id", "sentence"])

    tokenizer = Tokenizer(inputCol="sentence", outputCol="words")

    regexTokenizer = RegexTokenizer(inputCol="sentence", outputCol="words", pattern="\\W")
    # alternatively, pattern="\\w+", gaps(False)

    countTokens = udf(lambda words: len(words), IntegerType())

    tokenized = tokenizer.transform(sentenceDataFrame)
    tokenized.select("sentence", "words")\
        .withColumn("tokens", countTokens(col("words"))).show(truncate=False)

    regexTokenized = regexTokenizer.transform(sentenceDataFrame)
    regexTokenized.select("sentence", "words") \
        .withColumn("tokens", countTokens(col("words"))).show(truncate=False)
    # $example off$

    spark.stop()