examples/src/main/python/ml/onehot_encoder_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
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
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# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# $example on$
from pyspark.ml.feature import OneHotEncoder
# $example off$
from pyspark.sql import SparkSession

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

    # Note: categorical features are usually first encoded with StringIndexer
    # $example on$
    df = spark.createDataFrame([
        (0.0, 1.0),
        (1.0, 0.0),
        (2.0, 1.0),
        (0.0, 2.0),
        (0.0, 1.0),
        (2.0, 0.0)
    ], ["categoryIndex1", "categoryIndex2"])

    encoder = OneHotEncoder(inputCols=["categoryIndex1", "categoryIndex2"],
                            outputCols=["categoryVec1", "categoryVec2"])
    model = encoder.fit(df)
    encoded = model.transform(df)
    encoded.show()
    # $example off$

    spark.stop()