main/python/sort.py

0001 #
0002 # Licensed to the Apache Software Foundation (ASF) under one or more
0003 # contributor license agreements.  See the NOTICE file distributed with
0004 # this work for additional information regarding copyright ownership.
0005 # The ASF licenses this file to You under the Apache License, Version 2.0
0006 # (the "License"); you may not use this file except in compliance with
0007 # the License.  You may obtain a copy of the License at
0008 #
0009 #    http://www.apache.org/licenses/LICENSE-2.0
0010 #
0011 # Unless required by applicable law or agreed to in writing, software
0012 # distributed under the License is distributed on an "AS IS" BASIS,
0013 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014 # See the License for the specific language governing permissions and
0015 # limitations under the License.
0016 #
0017
0018 from __future__ import print_function
0019
0020 import sys
0021
0022 from pyspark.sql import SparkSession
0023
0024
0025 if __name__ == "__main__":
0026     if len(sys.argv) != 2:
0027         print("Usage: sort <file>", file=sys.stderr)
0028         sys.exit(-1)
0029
0030     spark = SparkSession\
0031         .builder\
0032         .appName("PythonSort")\
0033         .getOrCreate()
0034
0035     lines = spark.read.text(sys.argv[1]).rdd.map(lambda r: r[0])
0036     sortedCount = lines.flatMap(lambda x: x.split(' ')) \
0037         .map(lambda x: (int(x), 1)) \
0038         .sortByKey()
0039     # This is just a demo on how to bring all the sorted data back to a single node.
0040     # In reality, we wouldn't want to collect all the data to the driver node.
0041     output = sortedCount.collect()
0042     for (num, unitcount) in output:
0043         print(num)
0044
0045     spark.stop()