path: root/examples/src/main/python/sort.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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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#

from __future__ import print_function

import sys

from pyspark.sql import SparkSession


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: sort <file>", file=sys.stderr)
        exit(-1)

    spark = SparkSession\
        .builder\
        .appName("PythonSort")\
        .getOrCreate()

    lines = spark.read.text(sys.argv[1]).rdd.map(lambda r: r[0])
    sortedCount = lines.flatMap(lambda x: x.split(' ')) \
        .map(lambda x: (int(x), 1)) \
        .sortByKey()
    # This is just a demo on how to bring all the sorted data back to a single node.
    # In reality, we wouldn't want to collect all the data to the driver node.
    output = sortedCount.collect()
    for (num, unitcount) in output:
        print(num)

    spark.stop()